It is correct, and it does fix the domelight problem, but I haven't tested it on a civic with keyless yet. You're right on the wiring going through the factory radio that controls keyless and dome. I'm an installer at Circuit City, and I've done this fix about 7 times so far on civics....works every time. What sucks though is that the only 2 civics that had keyless, they never worked properly to begin with, so I couldn't test to see if this fixes the keyless not working or not. Oh well.
BTW, it is the bright neon green plug that used to plug into the OEM radio. The old method is to use a "T" harness from Metra to keep the factory radio plugged in and hanging behind the dash. This is just a pain in the ass and impractical.
The 2 wires are green/red and green/black. Just solder them together and domelight will work again.