I think there is a good chance the "late colors" are editor related. I'm not 100% sure, but in my IJ all of the transitions between different screens aren't colorized. Only when the transition is done, the colors appear. This makes it look like the colors are "late" a lot of the time, and unfortunately kinda ruins the experience.
Don't get med wrong, i think NetzZwerg did an amazing job with the coloring! But i don't think it's any secret that that the current editor for WPC machines has its limitations. But again, i could easily be wrong about it being editor related.
I had a Pin2DMD in my TSPP, and that didn't have the same issues, but as i understand it, a different editor is used for those games?