Art Project: 3-D Colors Cube

Here is my Art Project that I did on 2-D Art Design in College. We have to do a 4 rows or 16 each and use a 18'*24' square and make a 3D Cube. So left side is should be Red, Blue, Yellow, and Green and the right side be a different color.

Red/Dark Red, Red/Blue, Red/Purple, Red/Black

Blue/Dark Blue, Blue/Purple, Blue Green, Blue/Black

Yellow/Dark Yellow,  Yellow/Orange, Yellow/Green, Yellow/Black

Green/Dark Green, Green/Blue, Green/Violet, Green/Black

I did really well on it , but on the 9th on the yellow on the right side I drew Yellow-Orange and accidentally forgot to put a dark yellow . The only one I did blue and green one and shaded some of the colors and it looked fine. My Professor said that the red one that I did good on. I got a 85% on the project