HDR colors are different between recording & streaming

[The Ultimate Might]

I recently started streaming and I found that colors are different between recording & streaming.
Why doesn't OBS just stream recorded data? It looks simple, but it is not that simple, right?
But I think if OBS just stream the recorded data right away, it will look same as the recording. Am I not right?
Does YouTube process received data again, so the result becomes different than the source video data?
Streaming HDR has different colors, brightness... so when there is a bulb, its inner side is dark, it looks like a hole in the middle, I saw it while streaming Final Fantasy VII Remake. And everything looks washed slightly.
But the recording is fine.

[The Ultimate Might]

When can we stream HDR videos, simply just by pressing the button, like recording?