In the same folder there is separate "hdr" file, as far as im concerned disabling hdr as it is doesnt change that much. But you can keep it enabled and lower the numbers to your liking.
[HDR]
HIGH_PASS_LEVEL=0.45
BLOOM_BASE=1.0
BLOOM_LEVEL=5.5
BLUR_ITERATIONS=4
I dont know how much it changes in game when these values are modified.