I'm pretty sure at least in the last 2 years they were kinda limited in colors they could do because titanium is difficult to inject with color. Before that th

I'm pretty sure at least in the last 2 years they were kinda limited in colors they could do because titanium is difficult to inject with color. Before that they used stainless steel, I think they wanted to differentiate the frame from the non-Pro lineup to seem more "premium" But this year I guess they finally gave in and just use aluminum on the Pros and now they're free to color however they want.