In the 1.14.3 hotfix, when a player enters the Nether, the fog is supposed to appear dark red in the OG, warped forest, and crimson forest Nether biomes and blue in the Soul Sand valley. However in 1.16.0.51 Beta, the fog remains consistent in all Nether biomes and has the color of Overworld fog. Images are attatched to this issue for comparison purposes: