The way shading works on skins is not the same as the vanilla skin and a little drastic. On the screenshot my hand is supposed to be the same color and the few hand pixels and left side but the right side is SUPER bright and it bothers me and I really dont want to reconstruct my entire skin because of a lighting/shading issue.

Do you have optifine installed?

No optifine, I have the sodium family though

https://www.curseforge.com/minecraft/modpacks/neoteric-vanilla
modpack list
(plus hydrogen)