It's super easy, very cheap, and lots of fun to color your grout instead of using the same ol' same ol' off-the-shelf colors.
Step 1: First, Tile.
Tile up whatever you're tiling such as a backsplash, floor, wall.
Step 2: Test Colors.
There are two easy ways to do this: use Tints All or acrylic paint. Be aware that the colors may dry lighter once mixed with the grout so do a few sample test pieces.
Step 3: Mix.
My particular formula was about 2.5 lbs of unsanded grout and the full 8 ounce bottle of acrylic paint to get the most color possible. Add water slowly, mix, let it sit about ten minutes.
Step 4: Scare Yourself.
Grout as usual. Freak yourself out that you ruined your tile.
Step 5: Clean Up and Enjoy.
Once it all cleaned up, it turned out great!
Step 6: Revel.
Here's a comparison shot of the color in the bottle and the dried grout. Do a little dance that your grout is now unique and fun! Come on by my blog Flipping the Flip at humboldtartdept.blogspot.com for the full story, and much much more!