Build Color Wheel

Let's build a 2D color wheel step by step.

Here's what we'll end up with:

Click to view the full code

ColorWheelGuide.vue

<script setup lang="ts">
import "internationalized-color/css";
import {
  useColor,
  ColorWheelRoot,
  ColorWheelGradient,
  ColorWheelThumb,
} from "@urcolor/vue";

const { color } = useColor("hsl(210, 80%, 50%)");
</script>

<template>
  <ColorWheelRoot
    v-model="color"
    color-space="hsl"
    channel-angle="h"
    channel-radius="s"
    as="div"
    class="relative block size-64 overflow-hidden rounded-full"
    style="container-type: inline-size"
  >
    <ColorWheelGradient
      as="div"
      class="absolute inset-0 block"
    />
    <ColorWheelThumb
      class="
        size-4 rounded-full border-2 border-white
        shadow-[0_0_0_1px_rgba(0,0,0,0.3),0_2px_4px_rgba(0,0,0,0.3)]
        focus-visible:shadow-[0_0_0_1px_rgba(0,0,0,0.3),0_0_0_3px_rgba(66,153,225,0.6)]
      "
      aria-label="Color"
    />
  </ColorWheelRoot>
</template>

Step 1: Set up state

Start by importing the color model and creating a reactive color value.

<script setup lang="ts">
import { useColor } from "@urcolor/vue";  

const { color } = useColor("hsl(210, 80%, 50%)");  
</script>

useColor() creates a reactive color ref from any CSS color string. It returns a { color } object where color is a shallow ref holding the parsed Color instance.

Step 2: Add the root

ColorWheelRoot manages all the state and interactions. Tell it which color space and channels to map to the angle and radius.

<script setup lang="ts">
import { useColor, ColorWheelRoot } from "@urcolor/vue"; 

const { color } = useColor("hsl(210, 80%, 50%)");
</script>

<template>
  <ColorWheelRoot
    v-model="color"
    color-space="hsl"
    channel-angle="h"
    channel-radius="s"
  >
    <!-- children go here -->
  </ColorWheelRoot>
</template>

• color-space — the color space to work in (hsl, oklch, etc.)
• channel-angle — the channel mapped to the angular axis (rotation)
• channel-radius — the channel mapped to the radial axis (distance from center)

Step 3: Add the gradient

ColorWheelGradient renders the 2D circular gradient on a canvas.

<script setup lang="ts">
import {
  useColor,
  ColorWheelRoot,
  ColorWheelGradient, 
} from "@urcolor/vue";

const { color } = useColor("hsl(210, 80%, 50%)");
</script>

<template>
  <ColorWheelRoot
    v-model="color"
    color-space="hsl"
    channel-angle="h"
    channel-radius="s"
    class="relative block size-64 overflow-hidden rounded-full"
    style="container-type: inline-size"
  >
    <ColorWheelGradient class="absolute inset-0 block" /> 
  </ColorWheelRoot>
</template>

The root needs overflow-hidden rounded-full to clip the gradient to a circle, and container-type: inline-size so the component can calculate dimensions correctly.

Step 4: Add the thumb

ColorWheelThumb is the draggable handle. It's positioned automatically within the wheel.

<script setup lang="ts">
import {
  useColor,
  ColorWheelRoot,
  ColorWheelGradient,
  ColorWheelThumb, 
} from "@urcolor/vue";

const { color } = useColor("hsl(210, 80%, 50%)");
</script>

<template>
  <ColorWheelRoot
    v-model="color"
    color-space="hsl"
    channel-angle="h"
    channel-radius="s"
    class="relative block size-64 overflow-hidden rounded-full"
    style="container-type: inline-size"
  >
    <ColorWheelGradient class="absolute inset-0 block" />
    <ColorWheelThumb
      class="
        size-4 rounded-full border-2 border-white
        shadow-[0_0_0_1px_rgba(0,0,0,0.3),0_2px_4px_rgba(0,0,0,0.3)]
        focus-visible:shadow-[0_0_0_1px_rgba(0,0,0,0.3),0_0_0_3px_rgba(66,153,225,0.6)]
      "
      aria-label="Color"
    />
  </ColorWheelRoot>
</template>

TIP

All components are completely unstyled — the classes above are just an example using Tailwind CSS. Use any styling approach you prefer.

Start angle offset

Use start-angle to rotate where the wheel gradient begins (in degrees):

<template>
  <ColorWheelRoot
    v-model="color"
    color-space="hsl"
    :start-angle="90"
    channel-angle="h"
    channel-radius="s"
  >
    <!-- ... -->
  </ColorWheelRoot>
</template>

Different color spaces

Switch the color space and channel mapping for different wheel behaviors. For example, OKLCh:

<script setup lang="ts">
import { useColor } from "@urcolor/vue";

const { color } = useColor("oklch(0.6, 0.15, 210)");
</script>

<template>
  <ColorWheelRoot
    v-model="color"
    color-space="oklch"
    channel-angle="hue"
    channel-radius="chroma"
  >
    <!-- ... -->
  </ColorWheelRoot>
</template>

Listening to changes

Use @update:model-value for real-time updates (while dragging) and @value-commit for the final value (on release):

<script setup lang="ts">
// ...
const onColorChange = (color: Color) => {
  console.log("dragging", color.toString("css"));
};
const onColorCommit = (color: Color) => {
  console.log("committed", color.toString("css"));
};
</script>

<template>
  <ColorWheelRoot
    v-model="color"
    color-space="hsl"
    @update:model-value="onColorChange"
    @value-commit="onColorCommit"
    channel-angle="h"
    channel-radius="s"
  >
    <!-- ... -->
  </ColorWheelRoot>
</template>