Your color project must be zip compressed to be uploaded on to this server
Lighten the source project
in Finder, navigate to Documents -> Color Documents ; right click on your project and choose "show content of the package"
delete everything there is in the folder Archives : .tgz files are only used to restore the project to an earlier time. If you delete them, you will lose only that functionality, and the project size will be much smaller
empty the StillStore folder (it holds every still of the project)
Compress the project
in Documents -> Color Documents, right click on your project, and choose "compress" (or "add to the archive")