End flash purplish light saturation is affected by brightness values

The bug

The purplish tint generated by end light flashes are heavily affected by brightness values, causing it to look very different when the player has their brightness either set to maximum or set to moody.

Steps to reproduce

1. Go to the end.

2. Set your brightness at maximum.

3. Await until an end flash spawns.

4. Notice the purplish tint.

5. Repeat 2 to 4 with your brightness set to moody.

Expected result

The purplish light saturation would be consistent across different brightness values.

Observed result

The purplish tint is heavily affected by brightness values.