What colors match for interconnects?

RED I like to use for Right due to them both starting with R. White is left. Most equipment is marked red for right and white for left. It certainly doesn't matter though what system you use.

I always use red for right also.

The logic of using the time honored traditional Red for right and Black for left to denote channels is obvious. I think Bunnyrabid was referring to WAF type issues so if you furniture sheme is light wood and your gear silver what color. I say White, Grey or Black always works well but don't use color as a criteria myself. If you have Dark wood try medium or dark blue. Red works nicely with Black gear. But these things only become necessary if there is a WAF. I can tell you that personally I don't particularily like garrish colors like bright purple or pink or plaids. (I have some Salmon colored PCs that have black woven drains YECCH!!)

Red for right or positive. Red is always positive in electrical connections.