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.
Although most cells use uracil for RNA and thymine for DNA, there are exceptions. Some organisms have uracil instead of thymine in all their DNA, and other organisms have uracil in only some of their DNA.