It's kind of hard to explain. But in the eighth and last season of Diff'rent Strokes (when the show moved from NBC to ABC), it seemed like the lighting got darker/dimmer.

Maybe it's just my imagination since of course, the Drummond's penthouse was painted differently, too look more "pastel". And of course since, the Season 8 episodes are "newer", one would automatically assume that the videotaping technology/production values would much more sophisticated than before.

I know that DS for its last season, was shot at the ABC Television Center after spending the previous three years being shot at Universal Studios by Compact Video.