Give your OD kit a misting of regular Tan spray paint from Walmart. Not TOO much, or it will suck. Just spray a fine mist onto the olive drab gear and it will turn into a light tan. Do not try to make the vest look completely solid tan -- that is too much. You can make it work perfectly in the desert with just a little bit of paint.  

Quoted: Thanks, Does that light coat prevent paint from cracking and falling off? Can the light mistings be repeated for a more tan color with the same result, or does it start to crack off?

It is irrelevant if some of the paint cracks off. The overall color change and camouflage effect will be the same. If after a few weeks of heavy use, you can reapply the light mist as nessessary. Remember, the intent with using spray paint on gear is not to make it change color -- it is only possible to alter the colors ability to blend with the environment. A Green vest that is sprayed tan will still look green when viewed up close; but it will be a very TAN green that will work wonderfully in the desert.

I bought an old army rig that I am going to try to winter camouflage for hunting and so on. I doubt white would work but I think grey might.