Sky light broken? Lower hemisphere is solid color not working!

[tmammela]

I use sky light with static HDRI. I check "lower hemisphere is solid color", bottom reflections turn black. Then I adjust lower hemisphere color, nothing happens. Even if I turn it to white, bottom reflections are still black! I had this problem in 4.21, 4.22 and 4.23 at least.

Is this a bug or am I doing something wrong here?

[tmammela]

It seems sky light is also giving a green tint to all light that's coming from below horizon if bottom hemisphere is something else than fully black color.