I hate bringing back old threads like this, but I am having the same problem and didn’t see a solution posted anywhere.
I have many older users who have been asking me to “turn down the brightness” of the site for a while now because it was causing eye strain. These guys live on the site and spend many hours there going back and forth. They all seem to like the dark theme but are now complaining about some of the color choices (that’s easy) the biggest complaint has been about the social login boxes “looking crappy”. I tried making some adjustments to the color codes, but that didn’t do anything.
I searched but didn’t find another thread on this - although my taxonomy may not be employing technical terms. Apologies for the necropost in advance.