this addon allows you to color the skin of your elytra in the game. It's very simple.

 You just have to color a phantom membrane with the dye that you like, you can choose between the 16 Minecraft dyes, black, gray, light gray, green, lime, yellow, red, blue, light blue, purple, pink, orange, brown , white, cyan and magenta, then you must use it while you have the elytra equipped. 

and ready!! You can change the color whenever you want, your friends will be able to see the color of your elytra and you theirs. 

note: the dye will only be applied on yourself and all the elytra you use will have that color, if you color an elytra and give it to another player, when you use it it will have the default elytra color or the color that has been applied previously