Silver could make it difficult to distinguish from the white and grey of the Reboot and Game Only templates, and green could be difficult to distinguish from the Original Continuity template. I'm not sure what shades and template sizes you would be going with, so maybe that wouldn't be an issue, but I wanted to throw that out there
You could also perhaps have the RAT and Alternate Timeline templates be somwhat matching by making the Alternate Timeline template be a lighter blue (though, again, that could be difficult to distinguish from the Ben 23 template you're working on, depending on what shades & template sizes you pick.) Pink or purple might also be a good way to make one of the templates more easily distinugishable.
(Great job with the templates so far, btw, they look fantastic!)