I made this mod that substitutes the Far From Home suit with a 90's X-Men suit. However every texture had a "mask" file with which I did not know what to do. I mean for example "FFH_Arms" (file that i modded) and "FFH_Arms_Mask" showing the texture but with what looked like random colors to me.
During some cinematics the original color shows. Check this out: https://imgur.com/a/U0DaVO9 it looks terrible