Hmm, it does say that in the specs and the reviews. Taking the board out will be the best way to tell then. I don't know why they would use different appearing wires if they go to the same electrical point - maybe they ran out of solid yellow?
I looked at the pics on Newegg and I didn't see a sense wire on the mobo connector (would be a smaller gauge yellow wire that is tied to the main yellow wire on the mobo connector), but the pic isn't the best, so I'm not sure. There could also be a pot you can tweak in there as well.
BTW: Even though the PS is off/unplugged, there may be some caps with high voltage on them - so again, be careful. Don't mean to be repetitive, but don;t want to read about you in the obits...