I've seen that Size15s has a yellow E1e..... I'm sure he probably has other rare/limited production surefire lighs and parts.
It's Golden.
Or perhaps you mean this one?
Also Golden.
BTW, the "Purple Inspection Light" (photo by Shelby Chan) is a current SureFire product (there are threads here on CPF about it).
The DARPA Experimental Flashlights (DEF) were also production items although only specific quanities were produced for the project. Limited overspill were sold off as PKEF (PK Experimental Flashlights)
You may notice that the M500C proto-type you have posted is sitting on PK's desk.
I think its important to differentiate between limited/rare/one-off versions of known products (different colour versions for example), and proto-types.