my lighting AND objects are always tinted yellow

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.