Yes.. Off the shelf food color works just fine. I usually put 10 drops of food color and add 4 or 5 drops of water. It goes a long way. Be sure to wear gloves unless you don't mind your fingers being colored for a week. I understand that the GEL style food color works as well.
Now, the key is to wet your project with water first. This will cause the grain to stand up. Sand it back down with a 400 grit paper. Then apply your food color stain. Grain will only rise once when wet, so by wetting and sanding before you apply the stain, you will not end up with grain texture.
Oh, and I'd let your project dry for a good 24 hours before you apply a final finish like Lacquer or Poly. Otherwise the colors may run into your applicator and end up where you don't want it. Like wood stain, you can apply multiple coats to make your colors darker or stand better.
If you plan to use a lot of food color, you might want to consider buying it in bulk from a Cake supply store. But the standard grocery store pack should last you a long time.
