All desks currently come in the displayed colors on the site.
The iMax comes in Graphite while the iDesk does not. Basically the iMax is the iDesk with a printer shelf. In addition to the printer shelf, the iMax comes in Graphite as well as all the other iDesk colors. The design is slightly different between the iMax and iDesk. There is no place on the iDesk for hooking the shelf up.