diff --git a/src/renderer/webgl/atlas/CharAtlasUtils.ts b/src/renderer/webgl/atlas/CharAtlasUtils.ts
index 2bda420f..9bbd614a 100644
--- a/src/renderer/webgl/atlas/CharAtlasUtils.ts
+++ b/src/renderer/webgl/atlas/CharAtlasUtils.ts
@@ -17,7 +17,7 @@ export function generateConfig(scaledCharWidth: number, scaledCharHeight: number
     selection: null,
     // For the static char atlas, we only use the first 16 colors, but we need all 256 for the
     // dynamic character atlas.
-    ansi: colors.ansi.slice(0, 16)
+    ansi: colors.ansi.slice()
   };
   return {
     devicePixelRatio: window.devicePixelRatio,
diff --git a/src/renderer/webgl/atlas/WebglCharAtlas.ts b/src/renderer/webgl/atlas/WebglCharAtlas.ts
index a9cd8e7d..85496aa1 100644
--- a/src/renderer/webgl/atlas/WebglCharAtlas.ts
+++ b/src/renderer/webgl/atlas/WebglCharAtlas.ts
@@ -11,7 +11,6 @@ import { is256Color } from './CharAtlasUtils';
 import { clearColor } from './CharAtlasGenerator';
 import { DEFAULT_ATTR } from '../../../core/buffer/BufferLine';
 import { DEFAULT_COLOR } from '../../../common/Types';
-import { DEFAULT_ANSI_COLORS } from '../../../ui/ColorManager';
 import { IColor } from 'xterm';
 
 // In practice we're probably never going to exhaust a texture this large. For debugging purposes,
@@ -158,10 +157,10 @@ export default class WebglCharAtlas extends BaseCharAtlas {
   }
 
   private _getColorFromAnsiIndex(idx: number): IColor {
-    if (idx < this._config.colors.ansi.length) {
-      return this._config.colors.ansi[idx];
+    if (idx >= this._config.colors.ansi.length) {
+      throw new Error('No color found for idx ' + idx);
     }
-    return DEFAULT_ANSI_COLORS[idx];
+    return this._config.colors.ansi[idx];
   }
 
   private _getBackgroundColor(bg: number): IColor {
diff --git a/src/ui/ColorManager.ts b/src/ui/ColorManager.ts
index 923b2823..276b6e14 100644
--- a/src/ui/ColorManager.ts
+++ b/src/ui/ColorManager.ts
@@ -16,7 +16,7 @@ const DEFAULT_SELECTION = {
 
 // An IIFE to generate DEFAULT_ANSI_COLORS. Do not mutate DEFAULT_ANSI_COLORS, instead make a copy
 // and mutate that.
-export const DEFAULT_ANSI_COLORS = (() => {
+export const DEFAULT_ANSI_COLORS: IColor[] = (() => {
   const colors = [
     // dark:
     fromHex('#2e3436'),