chore: Standardize code, comments and docs on US-English spelling (#2707)

tests/card-controller/style-manager.browser.test.ts

@@ -7,9 +7,9 @@ import {
   createStillImageCardConfig,
 } from '../browser/test-utils';
 
-// A colour the dark theme sets and the card carries no other way. Reading it
-// back proves the stylesheet reached the card rather than merely compiling.
-// See src/scss/themes/dark.scss .
+// A color the dark theme sets and the card carries no other way. Reading it
+// back proves the stylesheet reached the card rather than merely compiling. See
+// src/scss/themes/dark.scss .
 const DARK_PRIMARY_BACKGROUND = '#111111';
 
 const mountThemed = async (themes: ThemeName[]) =>