The fourth challenge is to create a project using two primary colors and their secondary color. Primary colors are red, blue, and yellow. Secondary colors are green (blue + yellow), orange (red + orange), and purple (red + blue). You can use any shade of these colors (i. e. light blue, pink, pale yellow, etc), but you must pick two primary colors and use their secondary color. You can not mix any of the colors (no blue green, etc). You can also use black and white. I used yellow and blue to make green.