When I made my EIFOTI eyes, I wanted to include a split dye mask, so that you could further customize your eyes with the base you use. For those not in the know - Split Masks allow your characters actual eye colors to layer over the base, but not everywhere. Only where the mask color is. It can give some really neat effects depending on what your base is.
Dark bases don't show the colors well, but play around and see what you can do. You could put these on any eyes you want to. These are all previews over an upcoming eye base of mine that is almost solid white. The teal and purple you see in the images is my characters actual heterochromia eye colors.
No pay version, cause yeaaahhhh, no. I put more work into the ads then the masks, and it's all voluntary. Have fun!