There are two categories of color and one is the actual color from the pigments and the other is the pattern of color like light blend or bicolor or variegated and so on. This is not a real scientific study and perhaps the question might be"what colors or patterns occur too often? Light blend used to be mocked by judges who would say: " not another light blend" when judging seedlings or even at the shows. For some reason dark blend is more admired.
So the question could be re-stated and divided into to two questions:
(1)Which of the color patterns are the easiest or hardest to breed, or are the most common or perhaps least desired and what pattern is "very hot" right now(we know that answer is picotee).?
(2) What solid colors are the easiest, or most common or least desirable or coveted of the solid colors? And which of the solid colors are hard to breed? And what solid colors are your favorites?
Way too much to talk about when it comes to color in dahlias.
Barbie Pink may be on a list of desired colors . In the early 90s I considered Normandy Promise to be the best color of dahlias of all. Now I have dig up an old picture as you all have never heard of it.