Hello 👋🏼I am looking for a RUSt plugin in which a player has the opportunity to recolor the electrical cables.maybe you have a tip.

I am like 99% sure you can't do that

Can confirm 100% what Orange stated.
The server sends the IO lines as a collection of coordinates (corners) between IOEntity A's output and IOEntity B's input.
There is no color info or any such info sent from the server to the client, that is all handled client-side in "ClientIOLine" and thus can't be modified by uMod/Oxide.