Colors Has Changed Since Switched From W7 To W8

I'm playing a browser-based game where we use signature-photos, and some people including me like to go a little nuts here and make photos with transparent backgrounds, the only issue is that transparent backgrounds have a lot larger files than if you just change the background-color of the photo to whatever the background of the website is, which in this case is #111111. Anyway, this worked perfectly on Windows 7, but since I switched to Windows 8.1, the background colors of the photos has changed, either that or the colors themself has changed. When I printscreen the background of the website, it's still #111111 while as the color of the photos are #080808, can this be related?

I have talked to a lot of players on this game who runs Windows 8 who doesn't have this issue.

Here's a printscreen of what I'm referring to: Screenshot by Lightshot