diff --git a/src/renderer/webgl/ColorUtils.ts b/src/renderer/webgl/ColorUtils.ts
new file mode 100644
index 000000000..9efdeb9c6
--- /dev/null
+++ b/src/renderer/webgl/ColorUtils.ts
@@ -0,0 +1,14 @@
+/**
+ * @license MIT
+ * Copyright (c) 2018 The xterm.js authors. All rights reserved.
+ */
+
+import { IColor } from '../../ui/Types';
+
+export function getLuminance(color: IColor): number {
+  // Coefficients taken from: https://www.w3.org/TR/AERT/#color-contrast
+  const r = color.rgba >> 24 & 0xff;
+  const g = color.rgba >> 16 & 0xff;
+  const b = color.rgba >> 8 & 0xff;
+  return (0.299 * r + 0.587 * g + 0.114 * b) / 255;
+}
diff --git a/src/renderer/webgl/GlyphRenderer.ts b/src/renderer/webgl/GlyphRenderer.ts
index 6a6a873d0..9bd4573d0 100644
--- a/src/renderer/webgl/GlyphRenderer.ts
+++ b/src/renderer/webgl/GlyphRenderer.ts
@@ -4,7 +4,7 @@
  */
 
 import { createProgram, PROJECTION_MATRIX } from './WebglUtils';
-import { IColorManager, IRenderDimensions } from '../Types';
+import { IRenderDimensions } from '../Types';
 import { ITerminal } from '../../Types';
 import WebglCharAtlas from './WebglCharAtlas';
 import { IWebGL2RenderingContext, IWebGLVertexArrayObject, IRenderModel, IRasterizedGlyph } from './Types';
@@ -13,6 +13,8 @@ import { COMBINED_CHAR_BIT_MASK } from './RenderModel';
 import { fill, slice } from '../../common/TypedArrayUtils';
 import { NULL_CELL_CODE, WHITESPACE_CELL_CODE, CHAR_DATA_CHAR_INDEX } from '../../core/buffer/BufferLine';
 import { IBufferLine } from '../../core/Types';
+import { IColorSet } from '../../ui/Types';
+import { getLuminance } from './ColorUtils';
 
 interface IVertices {
   attributes: Float32Array;
@@ -96,7 +98,7 @@ export class GlyphRenderer {
 
   constructor(
     private _terminal: ITerminal,
-    private _colorManager: IColorManager,
+    private _colors: IColorSet,
     private _gl: IWebGL2RenderingContext,
     private _dimensions: IRenderDimensions
   ) {
@@ -216,7 +218,7 @@ export class GlyphRenderer {
 
     // TODO: Make fg and bg configurable, currently since the buffer doesn't
     // support truecolor the char atlas cannot store it.
-    const lumi = this._colorManager.getLuminance(this._colorManager.colors.background);
+    const lumi = getLuminance(this._colors.background);
     const fg = lumi > 0.5 ? 7 : 0;
     const bg = lumi > 0.5 ? 0 : 7;
 
@@ -297,7 +299,7 @@ export class GlyphRenderer {
     }
   }
 
-  public onThemeChanged(): void {
+  public onThemeChange(): void {
   }
 
   public render(renderModel: IRenderModel, isSelectionVisible: boolean): void {
diff --git a/src/renderer/webgl/RectangleRenderer.ts b/src/renderer/webgl/RectangleRenderer.ts
index 7399cc837..e047d7acf 100644
--- a/src/renderer/webgl/RectangleRenderer.ts
+++ b/src/renderer/webgl/RectangleRenderer.ts
@@ -4,13 +4,14 @@
  */
 
 import { ITerminal } from '../../Types';
-import { IColorManager, IRenderDimensions, IColor } from '../Types';
+import { IRenderDimensions } from '../Types';
 import { createProgram, expandFloat32Array, PROJECTION_MATRIX } from './WebglUtils';
 import { IRenderModel, IWebGLVertexArrayObject, IWebGL2RenderingContext, ISelectionRenderModel } from './Types';
 import { fill } from '../../common/TypedArrayUtils';
 import { INVERTED_DEFAULT_COLOR } from '../atlas/Types';
 import { is256Color } from '../atlas/CharAtlasUtils';
 import { DEFAULT_COLOR } from '../../common/Types';
+import { IColorSet, IColor } from '../../ui/Types';
 
 const enum VertexAttribLocations {
   POSITION = 0,
@@ -76,7 +77,7 @@ export class RectangleRenderer {
 
   constructor(
     private _terminal: ITerminal,
-    private _colorManager: IColorManager,
+    private _colors: IColorSet,
     private _gl: IWebGL2RenderingContext,
     private _dimensions: IRenderDimensions
   ) {
@@ -148,14 +149,14 @@ export class RectangleRenderer {
     this._updateViewportRectangle();
   }
 
-  public onThemeChanged(): void {
+  public onThemeChange(): void {
     this._updateCachedColors();
     this._updateViewportRectangle();
   }
 
   private _updateCachedColors(): void {
-    this._bgFloat = this._colorToFloat32Array(this._colorManager.colors.background);
-    this._selectionFloat = this._colorToFloat32Array(this._colorManager.colors.selection);
+    this._bgFloat = this._colorToFloat32Array(this._colors.background);
+    this._selectionFloat = this._colorToFloat32Array(this._colors.selection);
   }
 
   private _updateViewportRectangle(): void {
@@ -272,9 +273,9 @@ export class RectangleRenderer {
   private _updateRectangle(vertices: IVertices, offset: number, bg: number, startX: number, endX: number, y: number): void {
     let color: IColor | null = null;
     if (bg === INVERTED_DEFAULT_COLOR) {
-      color = this._colorManager.colors.foreground;
+      color = this._colors.foreground;
     } else if (is256Color(bg)) {
-      color = this._colorManager.colors.ansi[bg];
+      color = this._colors.ansi[bg];
     }
     if (vertices.attributes.length < offset + 4) {
       vertices.attributes = expandFloat32Array(vertices.attributes, this._terminal.rows * this._terminal.cols * INDICES_PER_RECTANGLE);
diff --git a/src/renderer/webgl/WebglCharAtlas.ts b/src/renderer/webgl/WebglCharAtlas.ts
index 6963e714f..a6bd40130 100644
--- a/src/renderer/webgl/WebglCharAtlas.ts
+++ b/src/renderer/webgl/WebglCharAtlas.ts
@@ -5,13 +5,14 @@
 
 import { DIM_OPACITY, IGlyphIdentifier, INVERTED_DEFAULT_COLOR, ICharAtlasConfig } from '../atlas/Types';
 import BaseCharAtlas from '../atlas/BaseCharAtlas';
-import { DEFAULT_ANSI_COLORS } from '../ColorManager';
 import { IRasterizedGlyph, IBoundingBox, IRasterizedGlyphSet } from './Types';
-import { FLAGS, IColor } from '../Types';
+import { FLAGS } from '../Types';
 import { is256Color } from '../atlas/CharAtlasUtils';
 import { clearColor } from '../atlas/CharAtlasGenerator';
 import { DEFAULT_ATTR } from '../../core/buffer/BufferLine';
 import { DEFAULT_COLOR } from '../../common/Types';
+import { IColor } from '../../ui/Types';
+import { DEFAULT_ANSI_COLORS } from '../../ui/ColorManager';
 
 // In practice we're probably never going to exhaust a texture this large. For debugging purposes,
 // however, it can be useful to set this to a really tiny value, to verify that LRU eviction works.
diff --git a/src/renderer/webgl/WebglRenderer.ts b/src/renderer/webgl/WebglRenderer.ts
index 15fe77d98..f7ad0e586 100644
--- a/src/renderer/webgl/WebglRenderer.ts
+++ b/src/renderer/webgl/WebglRenderer.ts
@@ -3,10 +3,8 @@
  * @license MIT
  */
 
-import { IRenderer, IRenderDimensions, IColorSet, IRenderLayer, FLAGS } from '../Types';
-import { ITheme } from 'xterm';
+import { IRenderer, IRenderDimensions, IRenderLayer, FLAGS } from '../Types';
 import { CharacterJoinerHandler, ITerminal } from '../../Types';
-import { ColorManager } from '../ColorManager';
 import { RenderDebouncer } from '../../ui/RenderDebouncer';
 import { GlyphRenderer } from './GlyphRenderer';
 import { LinkRenderLayer } from '../LinkRenderLayer';
@@ -22,6 +20,8 @@ import { EventEmitter2, IEvent } from '../../common/EventEmitter2';
 import { Disposable } from '../../common/Lifecycle';
 import { CHAR_DATA_CHAR_INDEX, CHAR_DATA_CODE_INDEX, CHAR_DATA_ATTR_INDEX, NULL_CELL_CODE } from '../../core/buffer/BufferLine';
 import { DEFAULT_COLOR } from '../../common/Types';
+import { IColorSet } from '../../ui/Types';
+import { getLuminance } from './ColorUtils';
 
 export const INDICIES_PER_CELL = 4;
 
@@ -43,7 +43,6 @@ export class WebglRenderer extends Disposable implements IRenderer {
   private _needsFullRefresh: boolean = false;
 
   public dimensions: IRenderDimensions;
-  public colorManager: ColorManager;
 
   private _onCanvasResize = new EventEmitter2<{ width: number, height: number }>();
   public get onCanvasResize(): IEvent<{ width: number, height: number }> { return this._onCanvasResize.event; }
@@ -52,20 +51,15 @@ export class WebglRenderer extends Disposable implements IRenderer {
 
   constructor(
     private _terminal: ITerminal,
-    theme: ITheme
+    private _colors: IColorSet
   ) {
     super();
 
-    const allowTransparency = this._terminal.options.allowTransparency;
-    this.colorManager = new ColorManager(document, allowTransparency);
-    if (theme) {
-      this.colorManager.setTheme(theme);
-      this._applyBgLuminanceBasedSelection();
-    }
+    this._applyBgLuminanceBasedSelection();
 
     this._renderLayers = [
-      new LinkRenderLayer(this._terminal.screenElement, 2, this.colorManager.colors, this._terminal),
-      new CursorRenderLayer(this._terminal.screenElement, 3, this.colorManager.colors)
+      new LinkRenderLayer(this._terminal.screenElement, 2, this._colors, this._terminal),
+      new CursorRenderLayer(this._terminal.screenElement, 3, this._colors)
     ];
     this.dimensions = {
       scaledCharWidth: null,
@@ -98,8 +92,8 @@ export class WebglRenderer extends Disposable implements IRenderer {
     }
     this._terminal.screenElement.appendChild(this._canvas);
 
-    this._rectangleRenderer = new RectangleRenderer(this._terminal, this.colorManager, this._gl, this.dimensions);
-    this._glyphRenderer = new GlyphRenderer(this._terminal, this.colorManager, this._gl, this.dimensions);
+    this._rectangleRenderer = new RectangleRenderer(this._terminal, this._colors, this._gl, this.dimensions);
+    this._glyphRenderer = new GlyphRenderer(this._terminal, this._colors, this._gl, this.dimensions);
 
     // Detect whether IntersectionObserver is detected and enable renderer pause
     // and resume based on terminal visibility if so
@@ -118,10 +112,10 @@ export class WebglRenderer extends Disposable implements IRenderer {
 
   private _applyBgLuminanceBasedSelection(): void {
     // HACK: This is needed until webgl renderer adds support for selection colors
-    if (this.colorManager.getLuminance(this.colorManager.colors.background) > 0.5) {
-      this.colorManager.colors.selection = { css: '#000', rgba: 255 };
+    if (getLuminance(this._colors.background) > 0.5) {
+      this._colors.selection = { css: '#000', rgba: 255 };
     } else {
-      this.colorManager.colors.selection = { css: '#fff', rgba: 4294967295 };
+      this._colors.selection = { css: '#fff', rgba: 4294967295 };
     }
   }
 
@@ -142,25 +136,20 @@ export class WebglRenderer extends Disposable implements IRenderer {
     }
   }
 
-  public setTheme(theme: ITheme | undefined): IColorSet {
-    if (theme) {
-      this.colorManager.setTheme(theme);
-      this._applyBgLuminanceBasedSelection();
-    }
+  public onThemeChange(colors: IColorSet): void {
+    this._applyBgLuminanceBasedSelection();
 
     // Clear layers and force a full render
     this._renderLayers.forEach(l => {
-      l.onThemeChanged(this._terminal, this.colorManager.colors);
+      l.onThemeChange(this._terminal, this._colors);
       l.reset(this._terminal);
     });
 
-    this._rectangleRenderer.onThemeChanged();
-    this._glyphRenderer.onThemeChanged();
+    this._rectangleRenderer.onThemeChange();
+    this._glyphRenderer.onThemeChange();
 
     this._refreshCharAtlas();
     this._refreshViewport();
-
-    return this.colorManager.colors;
   }
 
   public onWindowResize(devicePixelRatio: number): void {
@@ -245,7 +234,7 @@ export class WebglRenderer extends Disposable implements IRenderer {
       return;
     }
 
-    const atlas = acquireCharAtlas(this._terminal, this.colorManager.colors, this.dimensions.scaledCharWidth, this.dimensions.scaledCharHeight);
+    const atlas = acquireCharAtlas(this._terminal, this._colors, this.dimensions.scaledCharWidth, this.dimensions.scaledCharHeight);
     if (!('getRasterizedGlyph' in atlas)) {
       throw new Error('The webgl renderer only works with the webgl char atlas');
     }
diff --git a/src/ui/ColorManager.ts b/src/ui/ColorManager.ts
index c751c4424..6d68c58d1 100644
--- a/src/ui/ColorManager.ts
+++ b/src/ui/ColorManager.ts
@@ -103,14 +103,6 @@ export class ColorManager implements IColorManager {
     };
   }
 
-  // Coefficients taken from: https://www.w3.org/TR/AERT/#color-contrast
-  public getLuminance(color: IColor): number {
-    const r = color.rgba >> 24 & 0xff;
-    const g = color.rgba >> 16 & 0xff;
-    const b = color.rgba >> 8 & 0xff;
-    return (0.299 * r + 0.587 * g + 0.114 * b) / 255;
-  }
-
   /**
    * Sets the terminal's theme.
    * @param theme The  theme to use. If a partial theme is provided then default
diff --git a/src/ui/Types.ts b/src/ui/Types.ts
index cc3606848..ef725ba6e 100644
--- a/src/ui/Types.ts
+++ b/src/ui/Types.ts
@@ -5,7 +5,6 @@
 
 export interface IColorManager {
   colors: IColorSet;
-  getLuminance(color: IColor): number;
 }
 
 export interface IColor {