I was close enough with blue to get it, though my theory had me very suspicious about one of its entries. If I had been right, it'd be aa 4/5 for reasonableness, but given I was wrong, 5/5.
Spoilers
I thought blue was "types of lights on a car". Parking lights, brake lights, and...turn signals? I'd colloquially call them blinkers. But whatever you call them, "turn" and "signal" are, in that context, referring to the same thing, which would make a very poor connection.