In Foldit, EnzDes is a coloring option, found in the View menu. EnzDes coloring is very similar to CPK coloring.
The amino acid gallery shows how each amino acid looks with EnzDes coloring.
"EnzDes" apparently means "enzyme design". The Rosetta software, which is part of Foldit, contains an "EnzDes" module.
See CPK coloring for a full explanation of the colors used.