A reference I sketched, colored, and textured, till came to this result. This is the TMNT design in my viewpoint. Rather than bandanas, they wear shoulder pads with a Japanese symbol marking their abilities; for Leonardo, the symbol means water.
I changed it, ha. Instead I am enabling skin color, eye color, size, muscle tone, and an arm-strap symbol to take the place of the blue bandana . This goes for the other TMNT too, alike to my previous picture of Raphael.