The render style allows you to change a color's brightness, contrast, hue and saturation, but is not allowing you to change multiple things about a color at the same time (for instance brightness AND hue).

In previous versions of the program, you can do something like:

1) Take a light blue eye
2) Change the hue to green
3) Change the brightness to darker
4) End up with a dark green eye

In current CTA3, changing an aspect of the color overrides everything else, so in the example above you can only go from "light blue eye to light green eye" or "light blue eye to dark blue eye" but not both. It still looks like it is recording the other settings, it just doesn't show up. This seems like a bug.