Jade is a mod by Snownee, this small pack only changes the Jade GUI to give it a more modern, smooth and minimalistic look. If you'd like the dark version, you can find it on my profile.
Download the correct version for you. Copy the file into the Minecraft installation folder inside "resourcepacks". Enable it by selecting it from the resource packs menu on the game sttings. It should activate when you do this. However, if it does not, open Jade settings (maybe through a Mod Menu mod) and enable it there manually in: Mod Settings/Appearance/Theme.
