Hi there @Rat_Messiah
Welcome to the Unreal Forum! Do you have PPV(Post Process Volume) in your scene? If so, select the post process volume and look for white balance or temperature and try adjust in it there. You can also adjust tint under the color grading section. Let me know if that works. Thanks!
Maybe it’s the same issue as this thread? In newer engine versions there’s a cvar in the to control the texture format for Lumen, which can eliminate the yellow bias. I don’t know the name of it off the top of my head, but it’s something like “r.LumenTextureFormat” or “r.LumenColorFormat.”
I’m not in a position to check right now but I can later and will update here if you’re still stuck.
Update: It’s “r.Lumen.LightingDataFormat”
I will check it out
thank you, that was it, but why is that a problem in the first place?
The linked post has the explanation. Basically if you have 3 colors but only 32 bits, you end up splitting them unevenly. 11 bits for 2 colors and 10 bits for the 3rd. This causes a slight precision error every time light bounces, which in this cases causes it to become slightly yellower with each additional bounce. The alternative format is 64 bits, which is accurate enough to avoid noticeable precision errors.
Most of the time, in real world cases where everything isn’t perfectly white, this yellowing will not be noticeable at all - so increasing the memory cost may not be worth it. This is especially true if you have your materials albedo values outside of the plausible range for PBR materials. Unrealistically bright materials will bounce more light than they should, and cause any precision errors to become exaggerated.