You can use any transfer on any color. The difference is the paper itself.
A dark transfer is a white sheet so all white areas (or anything lacking color, including transparent) WILL be white. Then you would need to trim off any areas you would not want on your shirt. They are designed for colored shirts so that the white is white. I use dark transfers for all my shirts, including white. They do seem to me to be more vibrant that the light transfer paper.
A light transfer has a clear sheet. So anything white (or lacking color) will be clear. Which would be your shirt color. You could use them on any colored shirt if either you have no white in your design or do not mind if all white areas are your shirt color. They are designed to be used with white shirts. Even if you used them on a light colored shirt, let's say light pink, then all white areas would be light pink. So a design of Mickey would result in light pink eyes in this example.
I hope all of this makes sense.