How can I color powder?

Factual Questions
1

I’m looking to make a certain something for my girlfriend- I want to fill a fancy (empty) tequila bottle with colored powder, in layers, and maybe place a picture of us inside. I went to my friendly local hobby shop, but they didn’y have what I was looking for. I did find small jars of glitter, but I’m looking for more earthy tones (not shiny metallic).

I have a few ideas, maybe food coloring + salt. (Salt so’s the ants don’t get a whiff of it… the bottle has a cork, not a screw.)

Any ideas? And if my idea isn’t clear enough, lemme know.

2

Seems to me you want colored sand. Here’s one brand. I’d think you could find it at a craft shop (Ben Franklin, Hobby Lobby).

3

Colored sand is definitely the thing for earthy tones; there are lots of naturally occurring colors, as well as stained sands. However, if you want to do the food coloring and salt thing, I’ve made colored bath salts by using food-grade dyes in water solution; a few drops will intensely color a moderate amount of salt (some salt will dissolve, but just keep working it gently in a mortar). We finished it off by adding the concentrated salt/color mix to the rest of the batch in a ball mill (you can make a small ball mill from a bucket and some golf balls), but an electric mixer might do just as well – just go slow, and leave it on (and on, and on).

4

Try using powdered tempera paint to color white sand. Tempera paint is available at most art supply stores

5

Colored chalk may be powdered and used like powdered tempera.