Lol, thanks. xD I usually don't reply to RMXP topics anymore (because I have retired almost a year and a half ago), except if it's a question that catches my attention somehow. But I am still fairly active in the community because of ARC.
Yes, it is a system that works just fine in RMXP. The only thing that can pose a bit of a problem is that you have to adjust all graphics properly. You have to expect that all hair graphics are used at the same place so every hair graphic has to be positioned properly in the file. Basically the same problem if you have a visual equipment script, just with body parts. Our script allowed you to change the hair, the color of the hair (in form of hue), each eye separately, the color of each eye separately (again, hue change) and the skin color and gender (basically one out of 10 base sprites, 5 colors each for 2 genders). They are were the same size because otherwise we would have to bother additionally with positioning of the sprite parts (as I explained earlier in this post).