An excellent coder by the name of Pathos has managed to modify Reshade in order to change the skins of the dinosaurs in the game. Have a look at what's going around Reddit:
https://www.reddit.com/r/jurassicworldevo/comments/9tlgi3/93_rex_ingame_skin/
https://www.reddit.com/r/jurassicworldevo/comments/9srn8b/jurassic_world_evolution_tiger_raptor_reskin/
Extremely cool stuff. If you want to do it yourself you can look up the tool on GitHub called JWEM. Technically it is in the legal safezone since this is all user created content; however, if takedowns are issued on the Reddit I'll delete this thread. Just thought you guys might like to try this out; it has at least given me a reason to consider reinstalling the game.