End flash purplish light brightness is not affected by the brigthness settings

Since the fix of MC-301025, the purplish tint generated by end light flashes are completely unaffected by brightness values, causing it to look weaker on brighter settings and very strong and contrasty on darker settings. It would be expected that the brightness of the flashes would scale with the brightness settings, just not in the manner that caused the previous bug.

The three screenshots, which look nearly identical, are in the moody, default, and bright brightness settings. The lightmaps provided are accurate to vanilla for the moody, default and bright brightness settings. Note how the tops are very different, but the bottom is the same leading to significantly different contrast.

Relates to MC-301025.