Red, Blue, Purple, Cyan, Green, Lime, Orange, Yellow, Pink, White, and Black. Colors are very distinctive. If the color is too far away to tell them apart, then the hat color stuff wouldnt help much
They may be easily distinguishable for you (now), but different people have different ability to distinguish colours (to the degree of being clinically colour blind)—and this able also degrades with age.
Having pink have a top hat and red have a sprout on their heads make them distinguishable beyond just colour.