Its spelled COLOR here in America! LOL. I try to use a light COLOR. Most of my arrows have been capped and crested with a white base color and then fletched with 2 white and 1 flourescent yellow Blazer. The reason I've done this is for better visibility both for seeing point of impact and finding the arrow after the shot. It also helps determine the type of blood on the arrow. The white makes it pretty easy to tell if you hit lungs , guts, etc.