Objective: To color homemade toothpaste.

Which of the following solutions is more sound in terms of naive physics reasoning?

Pick your answer from:
(a). Mix the food coloring (if it's powdered) with a spoonful of vodka. You don't need much. It's just for fun anyway. Add it to your mixture. If your food coloring is liquid, just pour some in.
(b). Mix the food coloring (if it's powdered) with a spoonful of oil. You don't need much. It's just for fun anyway. Add it to your mixture. If your food coloring is liquid, just pour some in.
(a).