This theme will apply a nice colored theme to the Facebook chat. No other part of the site should be affected.
Changes:
- The chatbox size can be customized, it's bigger by default
- Message, and titlebar color is changed
- Incoming messages are given animations

Tip: I recommend picking a darker color so that the white text looks better. I added text a color option if you really want a lighter setup though.

https://decentm.com/contact.html