Hexadecimal values are used to represent color in computer programs primarily because they are easier for humans to interpret compared to binary numbers, as well as being a compact representation compared to using decimal. Each pair of hexadecimal digits represents a value from 0 to 255, which corresponds to the range of color values in the RGB (Red, Green, Blue) color model. This allows for a convenient and efficient way to represent a wide range of colors.
So, the correct reason is: They are easier for humans to interpret.