What, you don't like the clown-nose effect?
With PS, start with the Magic Wand tool. Experiment with tolerances and once you've created a good selection of just the the red area, mess around different Image>Adjustments controls like Color Balance and Hue/Saturation. I've never used Replace Color, but that might do exactly what you need.
You have some nice pics there, #4 is awesome. You can get rid of the purple fringing on his wrist and hand by using the Sponge tool since everything surrounding it is already gray. Also, I'd clone out the bottle in the first two.