Global Out-Of-Character Script

I have been trying to script a system where if someone types a command, in this case, “/gooc” into chat, then the text before their name will contain “[OOC]” and the text will be “Deep orange”.

I have tried using solutions such as using speaker:SetExtraData in my script, which I have seen in other threads, and some scripting tutorials.

Hopefully someone is able to help with this, and maybe I could learn about ChatService as well.
Sorry if this thread is small, I didn’t really know what else to add to this, if you have any questions, just reply and I’ll get back to you ASAP.