Ultra subtle color

You can create very subtle, desaturated colors like this by blending the color original with a black and white copy.  You can convert the original into black and white using Nik's Silver Efex Pro, Photoshop, Adobe Camera RAW or Lightroom, or some other software.  Then, copy the black and white image to the clipboard (Edit > copy) and paste it over the original (Edit > paste).  At this point, change the opacity of the floating layer until the result is mostly black and white but with a very subtle color palette.  I captured this portrait at a Civil War Battle reinactment in Georgia.