I have a PS2 connected to an Elgato HD using the PS2/PS3 cable that came with it. If I play games without OBS open, everything looks normal. The moment I open OBS, my TV screen darkens quite a bit. Everything just looks wrong. The same thing happens with the Elgato Game Capture HD software. The solution was to select Expanded HDMI Color Range. I was able to do this in the Elgato software, but not in OBS. OBS won't allow me to change the HDMI Color Range when Input is component. I attached a pic for you to see what I mean. The game image is representative of what appears on stream as well as on my TV screen. Switching Color Range from Partial to Full in the OBS source properties fixes the issue for the stream, but not for my TV screen. Adjusting the brightness on my TV and in OBS I am able to get something decent, but I'd rather have the games on my TV look the same whether I'm streaming or not without adjusting brightness levels back and forth all the time.