A belated welcome to SCF!
There are two Franklin stamps that are different colors, one darker than the other, does this mean that one is counterfeit?
No, no counterfeits here. But stamps of this design can get altered (perforations recut, perforations cut off to imitate coil stamps, forged overprint added) to try to imitate expensive stamps. Not the case here. Different color shades are often just from different printings of the same issue. The right stamp might be from a booklet pane.
The 2c strip of 3 is, as you might already know, is a Confederate States issue from 1863. This HAS been forged but is not engraved like your stamps are.
The 2 stamps below that strip are from the 1898 Trans-Mississippi issue.
An immediate worldwide reference is the StampWorld site which might be useful for just touring at this point if you haven't used it yet. Otherwise, Scott catalogs are available in your local library's reference section with some older ones often available for checkout. The "Information for collectors" in the front of every volume is a must-read but can be overwhelming even though you have a head start. But it can also answer a lot of questions, whch you can always bring here regardless.
Looking forward to more pictures.