diff --git a/.gitignore b/.gitignore
index 2bff224..cbd0275 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 build
 .idea
 local.properties
+gradle.properties
diff --git a/build.gradle.kts b/build.gradle.kts
index 0048a97..628aeeb 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,12 +1,10 @@
-import org.jetbrains.kotlin.fir.declarations.builder.buildResolvedImport
-
 plugins {
-    kotlin("multiplatform") version "1.4.0-rc"
+    kotlin("multiplatform") version "1.4.30"
     `maven-publish`
 }
 
 group = "nl.astraeus"
-version = "0.3.6-SNAPSHOT"
+version = "0.3.10-SNAPSHOT"
 
 repositories {
     maven { setUrl("https://dl.bintray.com/kotlin/kotlin-eap") }
@@ -17,21 +15,36 @@ repositories {
 kotlin {
     jvm()
     js(BOTH) {
-        browser()
-
-        //produceKotlinLibrary()
-    }
-    val hostOs = System.getProperty("os.name")
-    val isMingwX64 = hostOs.startsWith("Windows")
-    val nativeTarget = when {
-        hostOs == "Mac OS X" -> macosX64("native")
-        hostOs == "Linux" -> linuxX64("native")
-        isMingwX64 -> mingwX64("native")
-        else -> throw GradleException("Host OS is not supported in Kotlin/Native.")
+        browser {
+            testTask {
+                useKarma {
+                    useFirefox()
+                    //useChrome()
+                }
+            }
+        }
     }
 
     sourceSets {
-        val commonMain by getting {}
+        val commonMain by getting {
+
+        }
+        val commonTest by getting {
+            dependencies {
+                implementation(kotlin("test-common"))
+                implementation(kotlin("test-annotations-common"))
+            }
+        }
+        val jvmTest by getting {
+            dependencies {
+                implementation(kotlin("test-junit"))
+            }
+        }
+        val jsTest by getting {
+            dependencies {
+                implementation(kotlin("test-js"))
+            }
+        }
     }
 }
 
@@ -68,3 +81,4 @@ publishing {
         }
     }
 }
+
diff --git a/gradle.properties b/gradle.properties
index 6c04925..eb94736 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,6 +1,5 @@
 kotlin.code.style=official
 kotlin.js.compiler=both
 
-nexusUsername=
-nexusPassword=
-
+nexusUsername=deployment
+nexusPassword=nhPTzBWizph86j2Jz5KhPdiB4C
diff --git a/src/commonMain/kotlin/nl/astraeus/css/properties/Color.kt b/src/commonMain/kotlin/nl/astraeus/css/properties/Color.kt
index a08a5ce..ab058a3 100644
--- a/src/commonMain/kotlin/nl/astraeus/css/properties/Color.kt
+++ b/src/commonMain/kotlin/nl/astraeus/css/properties/Color.kt
@@ -1,9 +1,13 @@
 package nl.astraeus.css.properties
 
-class Color(
-    value: String,
-    val readOnly: Boolean = true
+import kotlin.math.max
+import kotlin.math.min
+
+open class Color(
+  value: String,
+  val readOnly: Boolean = false
 ) : CssProperty(value) {
+
 /*    val hue: Int? = null
     val saturation: Int? = null
     val lightness: Int? = null
@@ -41,42 +45,46 @@ class Color(
         return this
     }*/
 
-    companion object {
-        val auto = Color("auto")
-        val transparant = Color("transparant")
-        val initial = Color("initial")
-        val inherit = Color("inherit")
-        fun hex(hex: String) = Color("#$hex")
-        fun rgb(
-            red: Int,
-            green: Int,
-            blue: Int
-        ) = Color("rgb($red, $green, $blue)")
-        fun rgba(
-            red: Int,
-            green: Int,
-            blue: Int,
-            alpha: Double
-        ) = Color("rgba($red, $green, $blue, $alpha)")
-        fun hsl(
-            hue: Int,
-            saturation: Int,
-            lightness: Int
-        ) = Color("hsl($hue, $saturation%, $lightness%)")
-        fun hsla(
-            hue: Int,
-            saturation: Int,
-            lightness: Int,
-            alpha: Double
-        ) = Color("hsla($hue, $saturation%, $lightness%, $alpha)")
+  companion object {
+    val auto = Color("auto", true)
+    val transparant = Color("transparant", true)
+    val initial = Color("initial", true)
+    val inherit = Color("inherit", true)
 
-        private fun fromHex(
-            red: Int,
-            green: Int,
-            blue: Int
-        ) {
+    fun hex(hex: String) = Color("#$hex")
+    fun rgb(
+      red: Int,
+      green: Int,
+      blue: Int
+    ) = Color("rgb($red, $green, $blue)")
+
+    fun rgba(
+      red: Int,
+      green: Int,
+      blue: Int,
+      alpha: Double
+    ) = Color("rgba($red, $green, $blue, $alpha)")
+
+    fun hsl(
+      hue: Int,
+      saturation: Int,
+      lightness: Int
+    ) = Color("hsl($hue, $saturation%, $lightness%)")
+
+    fun hsla(
+      hue: Int,
+      saturation: Int,
+      lightness: Int,
+      alpha: Double
+    ) = Color("hsla($hue, $saturation%, $lightness%, $alpha)")
+
+    private fun fromHex(
+      red: Int,
+      green: Int,
+      blue: Int
+    ) {
 
-        }
     }
+  }
 
 }
diff --git a/src/commonMain/kotlin/nl/astraeus/css/properties/CssProperty.kt b/src/commonMain/kotlin/nl/astraeus/css/properties/CssProperty.kt
index 4301e7d..eed8318 100644
--- a/src/commonMain/kotlin/nl/astraeus/css/properties/CssProperty.kt
+++ b/src/commonMain/kotlin/nl/astraeus/css/properties/CssProperty.kt
@@ -5,7 +5,7 @@ interface CssValue {
 }
 
 open class CssProperty(
-    val value: String
+    var value: String
 ): CssValue {
 
     override fun css(): String = value
diff --git a/src/commonMain/kotlin/nl/astraeus/css/properties/HslaColor.kt b/src/commonMain/kotlin/nl/astraeus/css/properties/HslaColor.kt
new file mode 100644
index 0000000..4bb92d0
--- /dev/null
+++ b/src/commonMain/kotlin/nl/astraeus/css/properties/HslaColor.kt
@@ -0,0 +1,168 @@
+package nl.astraeus.css.properties
+
+import kotlin.math.abs
+import kotlin.math.max
+import kotlin.math.min
+
+class HslaColor(
+  val hue: Int,
+  val saturation: Int,
+  val lightness: Int,
+  val alpha: Double = 1.0
+): Color("hsla($hue,$saturation%,$lightness%,$alpha)") {
+
+  fun darken(amount: Int): HslaColor = HslaColor(
+    hue,
+    saturation,
+    max(0, lightness - amount),
+    alpha
+  )
+
+  fun lighten(amount: Int): HslaColor = HslaColor(
+    hue,
+    saturation,
+    min(100, lightness + amount),
+    alpha
+  )
+
+  fun saturize(amount: Int): HslaColor = HslaColor(
+    hue,
+    min(100, saturation + amount),
+    lightness,
+    alpha
+  )
+
+  fun desaturize(amount: Int): HslaColor = HslaColor(
+    hue,
+    max(0, saturation - amount),
+    lightness,
+    alpha
+  )
+
+  fun adjustHue(amount: Int): HslaColor {
+    var hue = this.hue + amount
+    while (hue < 0) {
+      hue += 360
+    }
+    while(hue > 359) {
+      hue -= 360
+    }
+
+    return HslaColor(
+      hue,
+      saturation,
+      lightness,
+      alpha
+    )
+  }
+
+  fun toRgba() = RgbaColor.fromHsla(this)
+
+  companion object {
+    private fun findValues(value: String, expectedNumber: Int): List<String> {
+      check(value.contains('(') && value.contains(')'))
+
+      val parts = value.split('(')[1].split(')')[0].split(',')
+
+      check(parts.size == expectedNumber)
+
+      return parts
+    }
+
+    fun fromString(value: String): HslaColor = when {
+      value.trim().startsWith("#") -> {
+        fromHex(value.substringAfterLast('#'))
+      }
+      value.trim().startsWith("hsla") -> {
+        val values = findValues(value, 4)
+        HslaColor(
+          values[0].trim().toInt(),
+          values[1].trim().toInt(),
+          values[2].trim().toInt(),
+          values[3].trim().toDouble()
+        )
+      }
+      value.trim().startsWith("hsl") -> {
+        val values = findValues(value, 3)
+        HslaColor(
+          values[0].trim().toInt(),
+          values[1].trim().toInt(),
+          values[2].trim().toInt()
+        )
+      }
+      value.trim().startsWith("rgba") -> {
+        val values = findValues(value, 4)
+        fromRgba(
+          values[0].trim().toInt(),
+          values[1].trim().toInt(),
+          values[2].trim().toInt(),
+          values[3].trim().toDouble()
+        )
+      }
+      value.trim().startsWith("rgb") -> {
+        val values = findValues(value, 3)
+        fromRgb(
+          values[0].trim().toInt(),
+          values[1].trim().toInt(),
+          values[2].trim().toInt()
+        )
+      }
+      else -> {
+        throw IllegalArgumentException("Unable to parse $value as color")
+      }
+    }
+
+    fun fromHex(value: String): HslaColor = fromRgba(RgbaColor.fromHex(value))
+
+    fun fromRgba(rgba: RgbaColor): HslaColor = fromRgba(rgba.red, rgba.green, rgba.blue, rgba.alpha)
+
+    fun fromRgb(
+      red: Int,
+      green: Int,
+      blue: Int,
+    ): HslaColor {
+      return fromRgba(red, green, blue, 1.0)
+    }
+
+    fun fromRgba(
+      red: Int,
+      green: Int,
+      blue: Int,
+      alpha: Double
+    ): HslaColor {
+      val r = red / 255.0
+      val g = green / 255.0
+      val b = blue / 255.0
+
+      val v = max(r,max(g,b))
+      val c = v - min(r,min(g,b))
+      val f = (1 - abs(v+v-c-1))
+      var h = if (c > 0) {
+        when (v) {
+          r -> {
+            (g-b)/c
+          }
+          g -> {
+            2+(b-r)/c
+          }
+          else -> {
+            2+(b-r)/c
+          }
+        }
+      } else {
+        0.0
+      }
+
+      if (h < 0) {
+        h += 6
+      }
+
+      return HslaColor(
+        (60*h).toInt(),
+        if (f>0) { ((c * 100)/f).toInt() } else { 0 },
+        (100*((v+v-c)/2)).toInt(),
+        alpha
+      )
+    }
+  }
+}
diff --git a/src/commonMain/kotlin/nl/astraeus/css/properties/Measurement.kt b/src/commonMain/kotlin/nl/astraeus/css/properties/Measurement.kt
index 01f49c7..8cbc1a0 100644
--- a/src/commonMain/kotlin/nl/astraeus/css/properties/Measurement.kt
+++ b/src/commonMain/kotlin/nl/astraeus/css/properties/Measurement.kt
@@ -11,28 +11,41 @@ open class Measurement(
         val normal = Measurement("normal")
 
         fun px(nr: Int) = if (nr == 0) { Measurement("0") } else { Measurement("${nr}px") }
-        fun px(nr: Double) = Measurement("${nr}px")
-        fun em(nr: Int) = Measurement("${nr}em")
-        fun em(nr: Double) = Measurement("${nr}em")
-        fun perc(nr: Int) = Measurement("${nr}%")
-        fun perc(nr: Double) = Measurement("${nr}%")
-        fun pc(nr: Int) = Measurement("${nr}pc")
-        fun pc(nr: Double) = Measurement("${nr}pc")
-        fun cm(nr: Int) = Measurement("${nr}cm")
-        fun cm(nr: Double) = Measurement("${nr}cm")
+        fun px(nr: Double) = nr.px
+        fun em(nr: Int) = nr.em
+        fun em(nr: Double) = nr.em
+        fun perc(nr: Int) = nr.perc
+        fun perc(nr: Double) = nr.perc
+        fun pc(nr: Int) = nr.pc
+        fun pc(nr: Double) = nr.pc
+        fun cm(nr: Int) = nr.cm
+        fun cm(nr: Double) = nr.cm
     }
 }
 
+val Int.px: Measurement
+    get() = Measurement("${this}${if (this == 0) { "" } else { "px"}}")
+val Int.em: Measurement
+    get() = Measurement("${this}${if (this == 0) { "" } else { "em"}}")
+val Int.perc: Measurement
+    get() = Measurement("${this}%")
+val Int.pc: Measurement
+    get() = Measurement("${this}pc")
+val Int.cm: Measurement
+    get() = Measurement("${this}cm")
 fun Int.px(): Measurement = Measurement.px(this)
+
+val Double.px: Measurement
+    get() = Measurement("${this}px")
+val Double.em: Measurement
+    get() = Measurement("${this}em")
+val Double.perc: Measurement
+    get() = Measurement("${this}%")
+val Double.pc: Measurement
+    get() = Measurement("${this}pc")
+val Double.cm: Measurement
+    get() = Measurement("${this}cm")
 fun Double.px(): Measurement = Measurement.px(this)
-fun Int.em(): Measurement = Measurement.em(this)
-fun Double.em(): Measurement = Measurement.em(this)
-fun Int.perc(): Measurement = Measurement.perc(this)
-fun Double.perc(): Measurement = Measurement.perc(this)
-fun Int.pc(): Measurement = Measurement.pc(this)
-fun Double.pc(): Measurement = Measurement.pc(this)
-fun Int.cm(): Measurement = Measurement.cm(this)
-fun Double.cm(): Measurement = Measurement.cm(this)
 
 open class LineHeight(value: String) : CssProperty(value) {
     companion object {
diff --git a/src/commonMain/kotlin/nl/astraeus/css/properties/RgbaColor.kt b/src/commonMain/kotlin/nl/astraeus/css/properties/RgbaColor.kt
new file mode 100644
index 0000000..a5fb42c
--- /dev/null
+++ b/src/commonMain/kotlin/nl/astraeus/css/properties/RgbaColor.kt
@@ -0,0 +1,107 @@
+package nl.astraeus.css.properties
+
+import kotlin.math.max
+import kotlin.math.min
+
+class RgbaColor(
+  val red: Int,
+  val green: Int,
+  val blue: Int,
+  val alpha: Double = 1.0
+): Color("rgba($red,$green,$blue,$alpha)") {
+
+  fun toHsla(): HslaColor = HslaColor.fromRgba(this)
+
+  companion object {
+    private fun findValues(value: String, expectedNumber: Int): List<String> {
+      check(value.contains('(') && value.contains(')'))
+
+      val parts = value.split('(')[1].split(')')[0].split(',')
+
+      check(parts.size == expectedNumber)
+
+      return parts
+    }
+
+    fun fromString(value: String): RgbaColor = when {
+      value.trim().startsWith("#") -> {
+        fromHex(value.substringAfterLast('#'))
+      }
+      value.trim().startsWith("hsla") -> {
+        val values = findValues(value, 4)
+        fromHsla(
+          values[0].toInt(),
+          values[1].toInt(),
+          values[2].toInt(),
+          values[3].toDouble()
+        )
+      }
+      value.trim().startsWith("hsl") -> {
+        val values = findValues(value, 3)
+        fromHsl(
+          values[0].toInt(),
+          values[1].toInt(),
+          values[2].toInt()
+        )
+      }
+      value.trim().startsWith("rgba") -> {
+        val values = findValues(value, 4)
+        RgbaColor(
+          values[0].toInt(),
+          values[1].toInt(),
+          values[2].toInt(),
+          values[3].toDouble()
+        )
+      }
+      value.trim().startsWith("rgb") -> {
+        val values = findValues(value, 3)
+        RgbaColor(
+          values[0].toInt(),
+          values[1].toInt(),
+          values[2].toInt()
+        )
+      }
+      else -> {
+        throw IllegalArgumentException("Unable to parse $value as color")
+      }
+    }
+
+    fun fromHex(value: String): RgbaColor {
+      TODO("Implement parsing hex to rgba")
+    }
+
+    fun fromHsla(hsla: HslaColor): RgbaColor = fromHsla(
+      hsla.hue,
+      hsla.saturation,
+      hsla.lightness,
+      hsla.alpha
+    )
+
+    fun fromHsl(
+      hue: Int,
+      saturation: Int,
+      lightness: Int
+    ): RgbaColor {
+      return fromHsla(hue, saturation, lightness, 1.0)
+    }
+
+    fun fromHsla(
+      hue: Int,
+      saturation: Int,
+      lightness: Int,
+      alpha: Double
+    ): RgbaColor {
+      val h = hue
+      val s = saturation / 100.0
+      val l = lightness / 100.0
+
+      val a = s * min(l, 1 - l)
+      fun f(n: Int): Int {
+        val k: Int = (n + h / 30) % 12
+        return (255 * (l - a * max(min(k - 3, min(9 - k, 1)), -1))).toInt()
+      }
+
+      return RgbaColor(f(0), f(8), f(4), alpha)
+    }
+  }
+}
diff --git a/src/commonTest/kotlin/nl/astraeus/css/TestColor.kt b/src/commonTest/kotlin/nl/astraeus/css/TestColor.kt
new file mode 100644
index 0000000..167edb1
--- /dev/null
+++ b/src/commonTest/kotlin/nl/astraeus/css/TestColor.kt
@@ -0,0 +1,71 @@
+package nl.astraeus.css
+
+import nl.astraeus.css.properties.*
+import kotlin.test.Test
+
+class TestColor {
+
+  @Test
+  fun testBuilder() {
+    val css = style {
+      val baseColor = HslaColor(20, 50, 50)
+      val baseColorRgb = RgbaColor.fromHsla(baseColor)
+
+      println("BaseColor: ${baseColor.value} - ${baseColorRgb.value}")
+
+      val darkerColor = baseColor.darken(10)
+      val darkerColorRgb = RgbaColor.fromHsla(darkerColor)
+      println("DarkerColor: ${darkerColor.value} - ${darkerColorRgb.value}")
+
+      val saturizedColor = baseColor.saturize(10)
+      val saturizedColorRgb = RgbaColor.fromHsla(saturizedColor)
+      println("SaturizedColor: ${saturizedColor.value} - ${saturizedColorRgb.value}")
+
+      val redColor = RgbaColor(0,255,0,1.0)
+      val redColorHsla = redColor.toHsla()
+      val shiftedColor = redColorHsla.adjustHue(120)
+      val shiftedColorRgb = shiftedColor.toRgba()
+
+      println("RedColor: ${redColor.value} - ${redColorHsla.value}")
+      println("ShiftedColor: ${shiftedColor.value} - ${shiftedColorRgb.value}")
+
+      select(".test") {
+        top(10.px)
+        left(4.em)
+
+        backgroundColor(
+          RgbaColor.fromHsla(baseColor.darken(10))
+        )
+
+        animationIterationMode(
+          Count.auto,
+          Count.auto,
+          Count.auto,
+          Count.auto,
+          Count.auto
+        )
+
+        child("li") {
+          color(Color.hsl(200, 50, 50))
+        }
+
+        select("> a") {
+          color(Color.hsl(200, 50, 50))
+        }
+      }
+    }
+
+    println(css.generateCss())
+
+    val css2 = style {
+      cls("button") {
+        fontSize(12.px)
+        color(Color.hsl(200, 50, 50))
+      }
+    }
+
+    println(css2.generateCss())
+
+  }
+
+}
\ No newline at end of file
diff --git a/src/commonTest/kotlin/nl/astraeus/css/TestCssBuilder.kt b/src/commonTest/kotlin/nl/astraeus/css/TestCssBuilder.kt
index 3aa9367..cabeb53 100644
--- a/src/commonTest/kotlin/nl/astraeus/css/TestCssBuilder.kt
+++ b/src/commonTest/kotlin/nl/astraeus/css/TestCssBuilder.kt
@@ -1,16 +1,20 @@
 package nl.astraeus.css
 
-object TestCssBuilder {
-/*
-    @Test
-    fun testBuilder() {
-        val css = CssBuilder()
+import nl.astraeus.css.properties.Color.Companion.hsl
+import nl.astraeus.css.properties.Color.Companion.rgba
+import nl.astraeus.css.properties.Count
+import nl.astraeus.css.properties.em
+import nl.astraeus.css.properties.px
 
-        css.style {
+object TestCssBuilder {
+
+    //@Test
+    fun testBuilder() {
+        val css = css {
 
             select(".test") {
-                top(10.px())
-                left(4.em())
+                top(10.px)
+                left(4.em)
                 backgroundColor(rgba(255, 255, 255, 0.75))
                 animationIterationMode(
                     Count.auto,
@@ -20,6 +24,9 @@ object TestCssBuilder {
                     Count.auto
                 )
 
+                child("li") {
+                    color(hsl(200,50,50))
+                }
 
                 select("> a") {
                     color(hsl(200, 50, 50))
@@ -28,6 +35,17 @@ object TestCssBuilder {
         }
 
         println(css)
-    }*/
+
+        val css2 = css {
+            cls("button") {
+                fontSize(12.px)
+                color(hsl(200, 50, 50))
+            }
+        }
+
+        println(css2)
+
+
+    }
 
 }