Well i thought that also. BUt the guy with the fry says they are fading into yellow, and the others are staying regular. Im saying how can you be sure that they are pure without verifying the parents and origin.
I have seen Trimacs with a lot of yellow as in the pictures, I have never seen a pure Xanthic Trimac. Not to say one couldnt exist, I just have never seen or heard of one.