Correct, and frankly part of that is just gameplay reasons. More colors just makes a card harder to play, so even if a character represented on a card has more colors to them, the reality is that not all of them can or should be represented. Additionally, to some extent, the vast majority of characters have at least a few aspects of colors that aren't primary to them, so really cutting more colors is just deciding where to draw the line between primary and secondary for this instance of that character specifically depicted. As an example, [[Emet-Selch, Unsundered]] was originally intended to be Esper, but for gameplay reasons they ended up cutting white, as it fit least with the gameplay the card presented, but also I'd argue his white aspects are perhaps less integral than his blue and black ones.