Why might different color paints react differently with the solvents used to remove varnish?

Explanation:

The main reason for this is the ingredients found in the paint. Different Ingredients are used to make different types of color paints, therefore when each of these paints is used in connection with the solvent the different chemicals in the paint create a certain reaction with the chemicals in the solvent, and each reaction may be different in each color depending on the chemical compound.

the answer is definitely c.