Dart APIunself_styleCustomColorsonGoldContainer onGoldContainer property Null safety Color? onGoldContainer final Implementation final Color? onGoldContainer; unself_style unself_style CustomColors onGoldContainer property CustomColors class Constructors CustomColors Properties gold goldContainer hashCode mauve mauveContainer onGold onGoldContainer onMauve onMauveContainer onVanilla onVanillaContainer runtimeType sourceGold sourceMauve sourceVanilla type vanilla vanillaContainer Methods copyWith harmonized lerp noSuchMethod toString Operators operator ==