This is a single image random dot stereogram (SIRDS). Viewed from the correct distance with the correct decoupling of convergence and focus of the viewer's eyes, a number of shapes appear to float above the surface of the piece.
This is an unusual piece for several reasons. I normally work from photo images. In this case, the pattern was created by SIRDS software. With SIRDS, the color choice is completely arbitrary. SIRDS is based on a pattern of color combinations across each row. The specific colors do not matter to the 3-D effect.