You went for the titanium grille, if I remember right. In my opinion, your vehicle exterior color theme has now been established to some degree as black/titanium. I would continue that theme and not paint the running boards if you decide to get them. Besides, you obviously liked the look of titanium on black when you replaced the grilles. The aluminum running boards are not very wide and by no means dominate the side view of the vehicle. Get input from the board, but follow your instincts which show that you have good taste, so far. Whatever you do, Whatever, don't paint the aluminum. my .02.