That looks like outdoor and indoor, so I'd expect them to be different, even if it's "just a game" and it's all simulated.
But anyway, look at the Properties of the video source. There's likely a mismatch between that and what the source actually is.
A common mismatch is Full or Partial/Limited color. That comes from the old analog TV broadcasts, where nothing is ever equal, so they overdrove it slightly to make sure that full-black and full-white at least, were displayed correctly. Then of course, everything in between only used part of the available range that could be sent. Digital doesn't have that problem, but the standard remains. Getting it wrong, results in it being slightly too bright or too dark, or slightly over-/under-saturated.
And there are other things too. Play with them until you get it right. Each source has its own set, and OBS has a set for the final output in Settings -> Advanced.