Note: I just confirmed, the dimensional distortion on Opassa Beach is, in fact, Green.
I have to 'fess up to being stupid here. The dimensional distortion that takes one between Dimensions is green, but the one that takes one to The Time Devourer is a redish color (puce red?).
When I checked before it didn't occur to me that I was checking on a save file that wasn't new game+ or continue+. Hence, only one distortion showed up. I thought I must have just misremembered that the gate to the DBT was different from the gate to the other dimension.
Yeah, that was incredibly stupid of me. Sorry.