Combine all that info with google search results and you'll be able to identify most of your discs (if not all). Mactracker or sites like everymac.com will be helpful too (you can check what OS version was bundled with which model).
Some of grey discs simply have model name printed. Some would work with other similar models (i.e. my G5 2.0 DP discs are working with 2.3 DP, first PM G4 OS 9 discs are working with my Clamshells perfectly etc).