I believe you are correct for you can only use the existing Render Styles in the Standard Edition.
But, there is a solution. Look in the market place for
EZColors.
You can use the EZColor colors to apply the different colors provided for the various character parts.
There is a video on the page showing how they work. You can get the bundle or just the individual packs (by character part) that you need.
Jeff
See my CTA Tutorials on the YouTube channel CTAStepByStep
Check out EZColors for CTA. The easy way to change Render Styled (RS) colors.