diff --git a/src/browser/Color.ts b/src/browser/Color.ts
index 3a2b5032..09c6a4f1 100644
--- a/src/browser/Color.ts
+++ b/src/browser/Color.ts
@@ -84,8 +84,6 @@ export function contrastRatio(l1: number, l2: number): number {
   return (l1 + 0.05) / (l2 + 0.05);
 }
 
-// TODO: Cache [bg][fg]: result, should probably be owned by ColorManager?
-
 function rgbaToColor(r: number, g: number, b: number): IColor {
   return {
     css: toCss(r, g, b),
diff --git a/src/browser/ColorContrastCache.test.ts b/src/browser/ColorContrastCache.test.ts
new file mode 100644
index 00000000..17e5df38
--- /dev/null
+++ b/src/browser/ColorContrastCache.test.ts
@@ -0,0 +1,43 @@
+/**
+ * Copyright (c) 2017 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { assert } from 'chai';
+import { ColorContrastCache } from 'browser/ColorContrastCache';
+
+describe('ColorContrastCache', () => {
+  let cache: ColorContrastCache;
+
+  beforeEach(() => {
+    cache = new ColorContrastCache();
+  });
+
+  it('should save and get color values', () => {
+    assert.strictEqual(cache.getColor(0x01, 0x00), undefined);
+    cache.setColor(0x01, 0x01, null);
+    assert.strictEqual(cache.getColor(0x01, 0x01), null);
+    cache.setColor(0x01, 0x02, { css: '#030303', rgba: 0x030303ff});
+    assert.deepEqual(cache.getColor(0x01, 0x02), { css: '#030303', rgba: 0x030303ff});
+  });
+
+  it('should save and get css values', () => {
+    assert.strictEqual(cache.getCss(0x01, 0x00), undefined);
+    cache.setCss(0x01, 0x01, null);
+    assert.strictEqual(cache.getCss(0x01, 0x01), null);
+    cache.setCss(0x01, 0x02, '#030303');
+    assert.deepEqual(cache.getCss(0x01, 0x02), '#030303');
+  });
+
+  it('should clear all values on clear', () => {
+    cache.setColor(0x01, 0x01, null);
+    cache.setColor(0x01, 0x02, { css: '#030303', rgba: 0x030303ff});
+    cache.setCss(0x01, 0x01, null);
+    cache.setCss(0x01, 0x02, '#030303');
+    cache.clear();
+    assert.strictEqual(cache.getColor(0x01, 0x01), undefined);
+    assert.strictEqual(cache.getColor(0x01, 0x02), undefined);
+    assert.strictEqual(cache.getCss(0x01, 0x01), undefined);
+    assert.strictEqual(cache.getCss(0x01, 0x02), undefined);
+  });
+});