While red and purple are the two most common stencil colors, purple paper is used more often. Unfortunately, once it dries it has a greenish-gold shimmer that can be difficult to read on darker skin tones. This sheen isn't as much of an issue on lighter complexions but can blend in with deeper shades of skin making the design hard to decipher.
Red stencil paper is a second option to consider. While it tends to be lighter than other options, the visibility remains clear and consistent. This makes it perfect as it doesn’t muddy up those contour lines and you can really make out all the directional shapes of the shadows.