I personally love the red lightning idea- ties into The Son from Clone Wars and provides a nice contrast to the blue of Exegol.
This is the only thing that makes it interesting to me… but with Lightning being blue everywhere else, and the Son not being in Live Action or any of the films, I think it would simply add confusion to an edit where the goal is to remove confusion and fix plot holes.
I don’t see it as something that needs to be explained, we see Palpatine absorb the power of the dyad and then he steps down in new (red) robes with glowing eyes again. I feel like it’s safe to say the audience would understand:
Dyad power-charged Palpatine = Far greater power than ever before = Red lightning color
The red could just be interpreted by the general audience as maximum Dark side power since red usually means Sith, and TCW fans would appreciate the connection to the Son in the Mortis arc.