You are welcome.
They are RGB, although it looks like Niz's website didn't have any of the RGB variant in stock.
This website seems to.
It does look like they probably make a 45g RGB one, but
this is the first place I found one in stock. Not sure if they make one in both 45g and standard wired instead of being Bluetooth.
You would like a nice vintage dome with slider board. I haven't used any of the modern "memchanical" boards marketed to gamers, which often have RGB. Chyros has some Youtube videos on them if you wanted to look.
With modern mechanicals though, I couldn't say. If I had to use modern tactiles, between those I have tried, I would choose Topre or Matias. They're really not even similar though. They're just a lot better, in my opinion, than anything MX I have tried.
Have you tried any other "mechanical" keyboards in order to determine where your tastes lie? Otherwise, NIZ boards are the only thing I can almost guarantee that you will like. I haven't tried them myself, but some people even prefer their feel and/or sound to Topre. Topre is just too different from everything else on the market to make recommendations based only on an interest in that.
What do you want in a switch?