I have a MKV file that I need to use in After Effects. So, since AE does not import that format, I've used FFmpeg to convert to MP4 losslessly. The MP4 file works fine on VLC, but when I try to import into AE the colors are all messed up.
The attached image shows the same MP4 file loaded into VLC (left) and After Effects (right).
The codec info is: H264 - MPEG-4 AVC (part 10) (avc1)
This happens only with the lossless MP4 extracted from the MKV. If I re-encode the same file, using Handbrake for example, it works, but with quality loss.
I managed to make it work using the ProRes codec. This way I get a near lossless file and it works on After Effects.
It's not the ideal solution since the file is much bigger, but at least it works.
Also, this issue happens with all Adobe apps. I tried to import the same file into Premiere Pro, Photoshop and even Animate. The colors are always messed up. And I've tested in two different computers, my Intel desktop and a Ryzen notebook. Same thing.