The video above demonstrates a common bug that has been reported by many Galaxy S6 Edge users. For some of you the auto brightness continues to dim the screen in the dark even if you do not have auto brightness turned on. This could be pretty frustrating if you were in a dark room, but still wanted a bright and vivid screen.
There is a fix. The fix was found by "ultimatewaffel". The fix requires a bit of mod know how, but is pretty simple. You will download the file that corresponds with your android version. One the file is downloaded you will replace the services.jar in stystem/framework with your new file. Be sure to set the permissions to rwrr and reboot your device. The bug should now be gone and your screen may be brighter than it has been in the past.
via XDA