My Dad said I would need a base and an acid, but I can't figure out which ones. What you are looking for is an indicator.
Indicators are chemicals that are different colors in different pH ranges.
A common indicator used is Phenolphthalein, which turns from clear to red over a pH range of 8.2 to 9.8. Phenolphthalein is a colorless acid solution. In the presence of a base, it loses two protons to make its conjugate base, which is a bright pink color. Another common indicator is Bromphenol Blue, which goes from yellow to blue over a pH range of 3 to 4.8. In addition, it's bleach, so do this in a well-ventilated kitchen or garage.