Guys, the color difference is the result of lighting.... The leather has not darkened one bit....
The holster on the right has returned to it's semi gloss finish, which helps to reflect the light a bit more as well. The left side photo was probably taken outside, compeletely different light source...
Leather conditioners like Connolly's Hide Food will darken a holster. A tiny amount of Kiwi won't.
But then again, if you like you holsters partially rotten and looking like the cat chewed on them, be my guest