Where do you put the accent color?

I recently got to go see this client to take on the dining room and to fluff up the office as a guest room.  It was a simple order: keep the black and ivory diamond rug and tan walls, bring in a neutral upholstered bed, crisp hotel bedding, and a pop of red -- the outgoing sofa was in a ruby hue and my client liked the effect.

So, where do you put the red?

On curvy lamps (to mimic the shape of the headboard)?

On side tables for a bigger punch?

Or keep it to the pillows--easiest should you change your mind and want to go for green on a whim.