Thankyou for the resposne Andrew, however there were no post process being used anywhere (including on the camera).
I loaded it up today (1 day later) and the light now stays bluish in the game. Nothing was changed, but I guess the Editor just needed to be restarted and/or needed some time to rest. It somehow works now without any changes. =p
Happened to me too. Couldn’t figure it out, but then read this, restarted ue4, and the light doesn’t change anymore. Wierd behavior (ver14.5.2). One thing to notice thought is that the play version had the right color and the stopped vieport had the wrong one.