I made it using a reference texture and went to the java folder and went to assets, and selected skins. After that I deleted every file in there and relaunched the game, loaded up a world, and left it. Went back to the folder, clicked on both files on there and since they both have encrypted names, i add .png at the end and if i select the skin instead of the cape i remove the .png from the name, but if it is the cape, I take the file of the custom cape copy the name of the actual cape and paste the name on the custom cape, put it in the folder and delete the original and then remove the .png or file name from the cape file being careful to not remove any of the name
