I came across this great tip from MCP that I have found very useful and wanted to share.

The easiest way to mess up color in a photo is when using levels and curves improperly.  Levels to an extent, and curves to an even greater extent, affect both luminosity (brightness) and color when you adjust them.

Many photographers love the look of high contrast, high definition, and vivid color.  You can use levels and curves to get great color.  I will not be discussing that today.  What I will be addressing is how you can add contrast and punch to an image without shifting colors.  If your image has nice color but needs a lift, you may add an s-curve or play in curves or with sliders in levels.

Once you are done, if you see the skin and overall color is too warm/orange, just change your blending mode to luminosity.  Yep – that is all you need to do.  It tell that adjustment layer to only affect luminosity NOT color. Done!!! Wasn’t that easy?