Quality loss after exporting

HELP! Everytime I export my files it always starts to lose quality. I would color grade my footage and it would mess up the colors after export. I've tried exporting in 1920x1080 with H.264 coded and restrict the quality to 80000Kbps/sec but it still won't give me the quality I want. What seems to be the explanation to this? and are there any solutions? thank you

Read these:

"Grading for Mixed Delivery: Cinema, Home, and Every Screen in Between" by Cullen Kelly
https://blog.frame.io/2019/10/14/gradin ... -delivery/

"How to Deal with Levels: Full vs. Video" by Dan Swierenga
https://www.thepostprocess.com/2019/09/ ... l-vs-video

and
"A Deeper Look at Consistent Color with QuickTime Tags From Resolve To YouTube & Vimeo on Wide Gamut Apple Monitors"
by Dan Swierenga
https://www.thepostprocess.com/2020/07/ ... ktime-tags

and I think they cover the issues and the solutions very well. Understanding color management is also helpful:

"Color Management for Video Editors"
https://jonnyelwyn.co.uk/film-and-video ... o-editors/