Hmm! Curious as to my MCM got colder results from a black intercooler. They never actually strapped the intercoolers to a car, only bench testing with a fan and some thermometers...
Exactly. I like MCM (well, Moog is annoying sometimes) but that is a flawed test. As above, Engineering Explained's video goes into a lot more detail. Just prepare yourself for complex math if you haven't seen it yet!
My own thoughts on it are; if you can barely notice the difference of a bigger intercooler on the bum dyno, then painting one black is going to be completely undetectable, but it might show up as a degree or 3 more on the dyno IATs......whoopee do, the engine won't go into thermal shock and turn to dust, so don't worry about it.