Vibrant Visuals: Nether Portal screen effect is black in the Overworld

When standing idle in a nether portal with Vibrant Visuals on, the screen effect is black, compared to a bright purple when Vibrant Visuals is off

How to reproduce:

Make a nether portal, light it and stand inside. step a little bit out of the portal but still be inside the block the portal is on. When vibrant visuals is off you should see a purple warping effect/texture on your screen, but when it is ON, that warping effect is black. I do not know if this is intentional but it looks weird.