A hint toggle should be enough with the yellow paint being part of it. The only issue would be game journalists accidentally turning it off.

@nightarix yellow paint trap would be fun if that is done once or twice on game, other time it would be real guide. That would be enough to put people on edge on every time they are following quest marker.

i think it'd be hilarious if a game pulled this kinda trick, lets you get used to a certain color being helpful, then suddenly it's a deathtrap if you follow it, pity it'd only work once or twice before you figure out how your getting tricked, assuming no use of external guides.