Without also participating in the class to know what "color schemes" you have studied it is difficult to offer a suggestion. Color scheme can mean any number of things. Like you may have studied "Monochromatic" color schemes, or graduated color wheel color schemes (going from like say yellow to orange to red to purple to blue to green back to yellow with the tertiary colors included) or did you study Complimentary color schemes (the opposing side of the color wheel, like Green's compliment is Red, Blue's is Orange, Purple is Yellow). Has Achromatic color scheme been discussed? (no color just value in shades of grays (this would make a cool background))
If you tell us what color schemes you studied then maybe we can offer suggestions more directed to the assignment. French braid is definitely a possibility as is log cabin, Pineapple, chinese coin or even a quilted depiction of the color wheel using a wedge ruler.