I agree that there are many things about the dogs which we do not know...and may never know...and how, for sure, without a dog speaking clear 'human' language, would we ever be completely certain of anyway.
I do know that my dogs and cats tend to choose certain colors of identical things...like blankets...they will lay on one color, but if you replace it with another color, will not get on it...change back, and they cuddle up again.