The color wheel is made up of three different types of colors - Primary, Secondary, and Tertiary. The primary colors are red, yellow, and blue. They are called primary for a couple of reasons. First, no two colors can be mixed to create a primary color.
RNA contains uracil and DNA Thymine. RNA has five bases, but DNA only four. DNA contains a deoxyribose sugar, but RNA contains ribose sugar. DNA is a double strand of nucleotides, but RNA a single strand.
Now - by complete chance - deamination of cytosine results in uracil. Had DNA not switched from uracil to thymine, the deamination damage to cytosine would be essentially impossible to detect. But since thymine is used by DNA, uracil can be correctly recognised as damaged and repaired back to cytosine with thymine as template.