Comment by egypturnash

Realistically, you're probably going to want to let the user choose the colors used for their parenthesis, and once you have that set up it's pretty easy to include one or more colorblind-friendly color schemes.

Panic's "Nova" does this. It lets you pick your palette for the parenthesis from about 30 choices. It also adds vertical lines along the left edge to show indentation level and lets you choose from the same palettes. There's three at the bottom of both palette lists designed for protanopia/deuteranopia/tritanopia.