Universal Indicator

 

There are two things that make Universal Indicator paper better than litmus paper

1. You only need one bit of paper instead of two.

2. It not only tells you whether the substance is acid or alkali; it also tells you whether it is a weak acid or a strong acid.

Here are what 3 of the substances I tested looked like when I used Universal Indicator liquid instead of paper. But what are A, B and C?