What are these plugs for?

I'm currently rebuilding an old pc of mine for a Christmas gift/learn more about building a PC and I can't figure what to do with these plugs whcih I think are for the RGB on the fans. I only see one header that matches them but I have 2 more that need to plug in. So am I just wrong about something or am I at the point where I just need one of those RGB controllers? The motherboard is an rog strix b450-f gaming ii.