diff --git a/src/common/color/convert-color.ts b/src/common/color/convert-color.ts
index 40d7e63311..5afac322e8 100644
--- a/src/common/color/convert-color.ts
+++ b/src/common/color/convert-color.ts
@@ -90,9 +90,9 @@ export const lab2rgb = (
   x = Xn * lab_xyz(x);
   z = Zn * lab_xyz(z);
 
-  const r = xyz_rgb(3.2404542 * x - 1.5371385 * y - 0.4985314 * z); // D65 -> sRGB
-  const g = xyz_rgb(-0.969266 * x + 1.8760108 * y + 0.041556 * z);
-  const b_ = xyz_rgb(0.0556434 * x - 0.2040259 * y + 1.0572252 * z);
+  const r = Math.round(xyz_rgb(3.2404542 * x - 1.5371385 * y - 0.4985314 * z)); // D65 -> sRGB
+  const g = Math.round(xyz_rgb(-0.969266 * x + 1.8760108 * y + 0.041556 * z));
+  const b_ = Math.round(xyz_rgb(0.0556434 * x - 0.2040259 * y + 1.0572252 * z));
 
   return [r, g, b_];
 };
diff --git a/src/common/color/convert-light-color.ts b/src/common/color/convert-light-color.ts
index 5834151bf6..db4bf38f67 100644
--- a/src/common/color/convert-light-color.ts
+++ b/src/common/color/convert-light-color.ts
@@ -8,9 +8,9 @@ export const temperature2rgb = (
 ): [number, number, number] => {
   const value = temperature / 100;
   return [
-    temperatureRed(value),
-    temperatureGreen(value),
-    temperatureBlue(value),
+    Math.round(temperatureRed(value)),
+    Math.round(temperatureGreen(value)),
+    Math.round(temperatureBlue(value)),
   ];
 };
 
@@ -59,10 +59,10 @@ const matchMaxScale = (
 };
 
 export const mired2kelvin = (miredTemperature: number) =>
-  Math.floor(1000000 / miredTemperature);
+  miredTemperature === 0 ? 1000000 : Math.floor(1000000 / miredTemperature);
 
-export const kelvin2mired = (kelvintTemperature: number) =>
-  Math.floor(1000000 / kelvintTemperature);
+export const kelvin2mired = (kelvinTemperature: number) =>
+  kelvinTemperature === 0 ? 1000000 : Math.floor(1000000 / kelvinTemperature);
 
 export const rgbww2rgb = (
   rgbww: [number, number, number, number, number],
diff --git a/src/common/color/hex.ts b/src/common/color/hex.ts
index a25b6d6442..af394ed85f 100644
--- a/src/common/color/hex.ts
+++ b/src/common/color/hex.ts
@@ -14,8 +14,8 @@ export const hexBlend = (c1: string, c2: string, blend = 50): string => {
   c1 = expandHex(c1);
   c2 = expandHex(c2);
   for (let i = 0; i <= 5; i += 2) {
-    const h1 = parseInt(c1.substr(i, 2), 16);
-    const h2 = parseInt(c2.substr(i, 2), 16);
+    const h1 = parseInt(c1.substring(i, i + 2), 16);
+    const h2 = parseInt(c2.substring(i, i + 2), 16);
     let hex = Math.floor(h2 + (h1 - h2) * (blend / 100)).toString(16);
     while (hex.length < 2) hex = "0" + hex;
     color += hex;
diff --git a/src/common/color/lab.ts b/src/common/color/lab.ts
index 4ba5558ad3..29dd50e61d 100644
--- a/src/common/color/lab.ts
+++ b/src/common/color/lab.ts
@@ -1,12 +1,13 @@
 // From https://github.com/gka/chroma.js
 // Copyright (c) 2011-2019, Gregor Aisch
 
-export const labDarken = (
-  lab: [number, number, number],
-  amount = 1
-): [number, number, number] => [lab[0] - 18 * amount, lab[1], lab[2]];
+export type LabColor = [number, number, number];
 
-export const labBrighten = (
-  lab: [number, number, number],
-  amount = 1
-): [number, number, number] => labDarken(lab, -amount);
+export const labDarken = (lab: LabColor, amount = 1): LabColor => [
+  lab[0] - 18 * amount,
+  lab[1],
+  lab[2],
+];
+
+export const labBrighten = (lab: LabColor, amount = 1): LabColor =>
+  labDarken(lab, -amount);
diff --git a/test/common/color/colors.test.ts b/test/common/color/colors.test.ts
new file mode 100644
index 0000000000..44c4a4f71e
--- /dev/null
+++ b/test/common/color/colors.test.ts
@@ -0,0 +1,35 @@
+import { describe, test, expect } from "vitest";
+import {
+  getColorByIndex,
+  getGraphColorByIndex,
+  COLORS,
+} from "../../../src/common/color/colors";
+import { theme2hex } from "../../../src/common/color/convert-color";
+
+describe("getColorByIndex", () => {
+  test("return the correct color for a given index", () => {
+    expect(getColorByIndex(0)).toBe(COLORS[0]);
+    expect(getColorByIndex(10)).toBe(COLORS[10]);
+  });
+
+  test("wrap around if the index is greater than the length of COLORS", () => {
+    expect(getColorByIndex(COLORS.length)).toBe(COLORS[0]);
+    expect(getColorByIndex(COLORS.length + 4)).toBe(COLORS[4]);
+  });
+});
+
+describe("getGraphColorByIndex", () => {
+  test("return the correct theme color if it exists", () => {
+    const style = {
+      getPropertyValue: (prop) => (prop === "--graph-color-1" ? "#123456" : ""),
+    } as CSSStyleDeclaration;
+    expect(getGraphColorByIndex(0, style)).toBe(theme2hex("#123456"));
+  });
+
+  test("return the default color if the theme color does not exist", () => {
+    const style = {
+      getPropertyValue: () => "",
+    } as unknown as CSSStyleDeclaration;
+    expect(getGraphColorByIndex(0, style)).toBe(theme2hex(COLORS[0]));
+  });
+});
diff --git a/test/common/color/compute-color.test.ts b/test/common/color/compute-color.test.ts
new file mode 100644
index 0000000000..c704982f4d
--- /dev/null
+++ b/test/common/color/compute-color.test.ts
@@ -0,0 +1,18 @@
+import { describe, it, expect } from "vitest";
+import {
+  computeCssColor,
+  THEME_COLORS,
+} from "../../../src/common/color/compute-color";
+
+describe("computeCssColor", () => {
+  it("should return CSS variable for theme colors", () => {
+    THEME_COLORS.forEach((color) => {
+      expect(computeCssColor(color)).toBe(`var(--${color}-color)`);
+    });
+  });
+
+  it("should return the input color if it is not a theme color", () => {
+    const nonThemeColor = "non-theme-color";
+    expect(computeCssColor(nonThemeColor)).toBe(nonThemeColor);
+  });
+});
diff --git a/test/common/color/convert-color.test.ts b/test/common/color/convert-color.test.ts
new file mode 100644
index 0000000000..c04e995b2c
--- /dev/null
+++ b/test/common/color/convert-color.test.ts
@@ -0,0 +1,54 @@
+import { describe, it, expect } from "vitest";
+import {
+  hex2rgb,
+  rgb2hex,
+  rgb2lab,
+  lab2rgb,
+  lab2hex,
+  rgb2hsv,
+  hsv2rgb,
+  rgb2hs,
+  hs2rgb,
+  theme2hex,
+} from "../../../src/common/color/convert-color";
+
+describe("Color Conversion Tests", () => {
+  it("should convert hex to rgb", () => {
+    expect(hex2rgb("#ffffff")).toEqual([255, 255, 255]);
+    expect(hex2rgb("#000000")).toEqual([0, 0, 0]);
+  });
+
+  it("should convert rgb to hex", () => {
+    expect(rgb2hex([255, 255, 255])).toBe("#ffffff");
+    expect(rgb2hex([0, 0, 0])).toBe("#000000");
+  });
+
+  it("should convert rgb to lab and back", () => {
+    const rgb: [number, number, number] = [12, 206, 7];
+    const lab = rgb2lab(rgb);
+    expect(lab2rgb(lab)).toEqual(rgb);
+  });
+
+  it("should convert lab to hex", () => {
+    const lab: [number, number, number] = [53.23288, 80.10933, 67.22006];
+    expect(lab2hex(lab)).toBe("#ff0000");
+  });
+
+  it("should convert rgb to hsv and back", () => {
+    const rgb: [number, number, number] = [255, 0, 0];
+    const hsv = rgb2hsv(rgb);
+    expect(hsv2rgb(hsv)).toEqual(rgb);
+  });
+
+  it("should convert rgb to hs and back", () => {
+    const rgb: [number, number, number] = [255, 0, 0];
+    const hs = rgb2hs(rgb);
+    expect(hs2rgb(hs)).toEqual([255, 0, 0]);
+  });
+
+  it("should convert theme color to hex", () => {
+    expect(theme2hex("red")).toBe("#ff0000");
+    expect(theme2hex("#ff0000")).toBe("#ff0000");
+    expect(theme2hex("unicorn")).toBe("unicorn");
+  });
+});
diff --git a/test/common/color/convert-light-color.test.ts b/test/common/color/convert-light-color.test.ts
new file mode 100644
index 0000000000..8585ba9893
--- /dev/null
+++ b/test/common/color/convert-light-color.test.ts
@@ -0,0 +1,50 @@
+import { describe, it, expect } from "vitest";
+import {
+  temperature2rgb,
+  mired2kelvin,
+  kelvin2mired,
+  rgbww2rgb,
+  rgbw2rgb,
+} from "../../../src/common/color/convert-light-color";
+
+describe("temperature2rgb", () => {
+  it("should convert temperature to RGB", () => {
+    expect(temperature2rgb(6600)).toEqual([255, 255, 255]);
+    expect(temperature2rgb(6601)).toEqual([255, 252, 255]);
+    expect(temperature2rgb(1900)).toEqual([255, 132, 0]);
+  });
+});
+
+describe("mired2kelvin", () => {
+  it("should convert mired to kelvin", () => {
+    expect(mired2kelvin(20)).toBe(50000);
+    expect(mired2kelvin(0)).toBe(1000000);
+  });
+});
+
+describe("kelvin2mired", () => {
+  it("should convert kelvin to mired", () => {
+    expect(kelvin2mired(6500)).toBe(153);
+    expect(kelvin2mired(2700)).toBe(370);
+    expect(kelvin2mired(0)).toBe(1000000);
+  });
+});
+
+describe("rgbww2rgb", () => {
+  it("should convert RGBWW to RGB", () => {
+    expect(rgbww2rgb([255, 0, 0, 255, 0])).toEqual([255, 128, 126]);
+    expect(rgbww2rgb([0, 255, 0, 0, 255])).toEqual([154, 255, 53]);
+    expect(rgbww2rgb([255, 0, 0, 255, 128], 1000)).toEqual([255, 75, 25]);
+    expect(rgbww2rgb([255, 0, 0, 255, 128], undefined, 5000)).toEqual([
+      255, 102, 81,
+    ]);
+    expect(rgbww2rgb([255, 0, 0, 255, 128], 3000, 4000)).toEqual([255, 98, 73]);
+  });
+});
+
+describe("rgbw2rgb", () => {
+  it("should convert RGBW to RGB", () => {
+    expect(rgbw2rgb([255, 0, 0, 255])).toEqual([255, 128, 128]);
+    expect(rgbw2rgb([0, 255, 0, 0])).toEqual([0, 255, 0]);
+  });
+});
diff --git a/test/common/color/hex.test.ts b/test/common/color/hex.test.ts
new file mode 100644
index 0000000000..08e01f5d03
--- /dev/null
+++ b/test/common/color/hex.test.ts
@@ -0,0 +1,30 @@
+import { describe, it, expect } from "vitest";
+import { expandHex, hexBlend } from "../../../src/common/color/hex";
+
+describe("expandHex", () => {
+  it("should expand a 3-digit hex code to 6 digits", () => {
+    expect(expandHex("#abc")).toBe("aabbcc");
+  });
+
+  it("should return a 6-digit hex code unchanged", () => {
+    expect(expandHex("#abcdef")).toBe("abcdef");
+  });
+});
+
+describe("hexBlend", () => {
+  it("should blend two hex colors with default blend value", () => {
+    expect(hexBlend("#000000", "#ffffff")).toBe("#7f7f7f");
+  });
+
+  it("should blend two hex colors with a specified blend value", () => {
+    expect(hexBlend("#ff0000", "#0000ff", 25)).toBe("#3f00bf");
+  });
+
+  it("should return the first color if blend is 100", () => {
+    expect(hexBlend("#ff0000", "#0000ff", 100)).toBe("#ff0000");
+  });
+
+  it("should return the second color if blend is 0", () => {
+    expect(hexBlend("#ff0000", "#0000ff", 0)).toBe("#0000ff");
+  });
+});
diff --git a/test/common/color/lab.test.ts b/test/common/color/lab.test.ts
new file mode 100644
index 0000000000..3824d5d5b0
--- /dev/null
+++ b/test/common/color/lab.test.ts
@@ -0,0 +1,34 @@
+import { describe, it, expect } from "vitest";
+import {
+  labDarken,
+  labBrighten,
+  type LabColor,
+} from "../../../src/common/color/lab";
+
+describe("labDarken", () => {
+  it("should darken the color by the default amount", () => {
+    const lab: LabColor = [50, 20, 30];
+    const result = labDarken(lab);
+    expect(result).toEqual([32, 20, 30]);
+  });
+
+  it("should darken the color by a specified amount", () => {
+    const lab: LabColor = [50, 20, 30];
+    const result = labDarken(lab, 2);
+    expect(result).toEqual([14, 20, 30]);
+  });
+});
+
+describe("labBrighten", () => {
+  it("should brighten the color by the default amount", () => {
+    const lab: LabColor = [50, 20, 30];
+    const result = labBrighten(lab);
+    expect(result).toEqual([68, 20, 30]);
+  });
+
+  it("should brighten the color by a specified amount", () => {
+    const lab: LabColor = [50, 20, 30];
+    const result = labBrighten(lab, 2);
+    expect(result).toEqual([86, 20, 30]);
+  });
+});
diff --git a/test/common/color/rgb.test.ts b/test/common/color/rgb.test.ts
new file mode 100644
index 0000000000..fceeada00b
--- /dev/null
+++ b/test/common/color/rgb.test.ts
@@ -0,0 +1,41 @@
+import { describe, it, expect } from "vitest";
+import {
+  luminosity,
+  rgbContrast,
+  getRGBContrastRatio,
+} from "../../../src/common/color/rgb";
+
+describe("luminosity", () => {
+  it("calculates the correct luminosity for black", () => {
+    expect(luminosity([0, 0, 0])).toBe(0);
+  });
+
+  it("calculates the correct luminosity for white", () => {
+    expect(luminosity([255, 255, 255])).toBe(1);
+  });
+
+  it("calculates the correct luminosity for red", () => {
+    expect(luminosity([255, 0, 0])).toBe(0.2126);
+  });
+});
+
+describe("rgbContrast", () => {
+  it("calculates the correct contrast ratio between black and white", () => {
+    expect(rgbContrast([0, 0, 0], [255, 255, 255])).toBe(21);
+    expect(rgbContrast([255, 255, 255], [0, 0, 0])).toBe(21);
+  });
+
+  it("calculates the correct contrast ratio between red and white", () => {
+    expect(rgbContrast([255, 0, 0], [255, 255, 255])).toBeCloseTo(4);
+  });
+});
+
+describe("getRGBContrastRatio", () => {
+  it("calculates the correct rounded contrast ratio between black and white", () => {
+    expect(getRGBContrastRatio([0, 0, 0], [255, 255, 255])).toBe(21);
+  });
+
+  it("calculates the correct rounded contrast ratio between red and white", () => {
+    expect(getRGBContrastRatio([255, 0, 0], [255, 255, 255])).toBe(4);
+  });
+});