Hi,
I've been sorting through and cataloging all the used stamps I have accumulated, and this particular stamp decided to be an obstacle.
Where the date is located, one stamp is noticeably darker in that area (and generally all-around in the design) while the other is noticeably lighter. Just want to make sure I'm not missing anything since it has been two years since it was released

Would it be a printing matter and just no difference?
The same thing applies to #4141, one doesn't look the same as the others (it's got a more peach color on the lower right).
Thanks in advance.
[P.S. I'm not 14-years-old, don't know how that happened, heh.]