Mathmatical truth depends on logic. Logic depends on what we perceive.
Moral is a social thing. We can survive better that way.
Colours and everything we can perceive is determined by the physical laws of our universe. We do not know why or how they came into existance, yet.
There is nothing transcendental about that.

Assuming there is nothing beyond what we can perceive is no error, it is no belief, it is just nothing more than we can possibly know and therefore pragmatic and scientific.