I have been using Lightroom for quite a while. I have Adobe Lightroom CC 2015.
This evening after editing photos when I switched from the Develop Module and the Library Module the image changed color, and perhaps the exposure changed slightly.
This has never happened, any ideas?
Can you post a screen shot of the LR windows both for Library module and Develop module.
This is often a symptom of a display profile that is corrupt or incompatible with Lightroom. To quickly troubleshoot this, temporarily set your profile to sRGB, as described in this article: http://www.lightroomqueen.com/articles-page/how-do-i-change-my-monitor-profile-to-check-wh ether-its-corrupted/
If that doesn't help, try unchecking the option Preferences > Performance > Use Graphics Processor.