Howdy -
Once you get this you go D'OH! as it is really easy.
Lemme help!
1) select the colour bits you want to change
(use SELECTION=>COLOR RANGE, it is a good thing for stuff like cars and objects with solid colours)
2) use the Hue Saturation thang (IMAGE=>ADJUSTMENTS=>Hue Saturation), using the hue slider you can dial up whatever colour you want.
The example below took me (literally) less than a minute to do (the pros here will probably notice that

)
If you want different bits in different colours, just mask off one section of the object and use a separate colour shift for each section.
If you want REAL control, learn to use the
Adjustment Layers (that little button at the bottom of the LAYERS pallette that looks like a bad Yin-Yang symbol

)... they allow you to totally control colours and the shift is NOT permanent and you can change and update it at any time.
_________________
_________________________________
THIS SITE REALLY DOESN'T EXIST
the way our EGO THINKS IT MIGHT!
_________________________________