I have always heard that if you are accurate with value you can really play around with color and still have the image "read" as 3-dimensional. I proved this to myself years ago when I painted Vibracolor Apples
. I figured it would be easier if I did a value study first, and then painted on top of that, making sure each color matched the value underneath it. For the first one I picked random colors for each stroke. When I decided to do it again yesterday, I picked a new color for each object. You can choose either of these methods.
For the value study, if you are using oil, lay down a thin ground with burnt umber and OMS - wipe this evenly with a paper towel so it's a fairly medium value. Then paint in the darks with a brush and more paint. Wipe off the lights with paper towel or q-tips, dipping in OMS for maximum wipe-age.
You can feel free to paint from my photo, set up your own still life, or use whatever subject you like. If you can, please post a photo of your subject next to your painting. If you don't know how don't worry about it - just talk about what you changed in the description. And tell us if you enjoyed this shift or if it was totally frustrating. : )
Most of all, have fun!