Well, it's the colour scheme of the G1 Magnus toy, it shouldn't have too much blue!
Should have more red though - shoulders, head, lower arms and outside plates on the legs were blue, with most of the chest being red. Really the white on the original Ultra Magnus' humanoid mode is more of a trim colour, in my opinion.
It's based on the G1 cab Karl, not the full armoured robot.
Not really meant as a dig as such, it is more that my brain is wired in such a way that I don't see the cab as existing as a separate entity - to me Ultra Magnus is a car carrier that turns into a single large humanoid mode - the cab is just a part of him which gets swallowed up in the transformation. It is probably because I was mostly familiar with Magnus from the Marvel Comic, where he is treated that way. Because of that I immediately think of Magnus as being mostly blue in his humanoid mode, with a white cab section in vehicle mode.
I can see what they are doing, it just seems odd to my way of thinking.
I have liked a few white 'Magnus' homage toys (the repaints of Classics Voyager Prime and G2 laser Rod survived a recent clear-out), but that's down mostly to liking white on toys. They've never evoked the original Ultra Magnus for me as that full robot hardly had any white on it!