B:TB&tB episode 10 "The Eyes of Despero!" directed by Ben Jones.
For the teaser of episode 10, we have Dr Fate and Batman taking on Wotan in an astral landscape. I remember Nolan Obena looking at some Steve Ditko stuff for inspiration on the second background. Needless to say, I think this is as colorful as we ever got in the backgrounds.
"Batman: The Brave and the Bold" ™Warner Bros. Animation.