Spectacular colors can make an ordinary photograph into a "Leroy Neiman" type painting !! He was one of the 10 best artists in the world decades ago. During his fall from his elite status - he was commisioned to make his famous paintings of the 76 Olympics.
Color Posterizations are fun and easy to create - We printed up dozens of post cards and a set of 17 x 25's , they were all sold within hours.
After you create the colors (using curves) then INVERT them and then use the HUE / SATURATION sliders to watch the different color combinations that are possible. Then turn down saturation and bring it in slowly to the desired effect.