very fun topic, Jester. glad you thought of it bro.
and yeah Ryo looks like you had the same idea as I did with the colors, just a few differences.
I think their colors are perfect for each turtle.
and, a funny thing about the reference to yellow...
in the first turtles arcade game, Mikey is more of a yellow color than orange... and if you'll notice, the joystick on the arcade machine for Mikey is clearly YELLOW, and not orange... what was Konami thinking? or maybe they just ran out of orange paint?