add this in engine.ini
r.SceneColorFormat=3
r.Tonemapper.GrainQuantization=1
r.Tonemapper.Quality=5
r.Tonemapper.Sharpen=0.5
r.Color.Max=0.80
r.Color.Min=-0.015
r.Color.Mid=1.00
- - - Updated - - -
result https://imgur.com/a/0oGad1M
if it still looks dark for you, try change r.gamma up to 255