Black and White Line Patterns to Color

Students created three 3-D geometric shapes.  2 out of the 3 shapes are to be different and at different heights.  On those shapes, they drew black line patterns.  They then glued those down onto watercolor paper.  The line paper continued off of the paper.  They then only watercolored the paper.  The sections that they painted were created by the line patterns.  The sections had to be different colors.  So for example, blue and blue cannot be next to each other.  They would have to choose another color.  However, the same color can be used more than once.