-/**
- * Returns a colour three shades darker.
- *
- * We use darker text to indicate unselected buttons, lighter text for selected. Note you can't
- * guarantee that darkerThan/brighterThan undo each other, as they may result in black/white.
+ /**
+ * Returns a colour three shades darker. Note you can't guarantee that
+ * brighterThan reverses this, as darkerThan may result in black.