$$ Create a solution that allows the user to enter the names of two primary colors to be mixed. If the user enters anything other than $$red$,$blue$,$ or $$yellow$,$ the program should display an error message. Otherwise, the program should display the name of the secondary color that results by mixing the two primary colors.

$$ The colors red, blue and yellow are primary colors. When you mix $2$ primary colors you get the secondary colors as follows: Red and blue make purple. Red and yellow make orange. Blue and yellow make green. C$++$