Well you can learn all you need to know in the product description.
RGB is just multi-colour, something you can fiddle around with.
LED is just single colour
Cherry Brown/Red/Blue etc etc are just different switches which is someones personal preference.
LUX & RAPIDFIRE as far as I'm aware are just different models, aesthetically different.
So what are the real differences between the Cherry Brown/Red/Blue switches?
They keyboard guide has a description of each of the key switches. The MX Speed switches are closely similar the MX Reds, but have a higher actuation point meaning do don't need to press as much to get the key to register.
Might be easier to get somewhere to try them out to see for yourself.
https://forums.overclockers.co.uk/showthread.php?t=18624243&highlight=testAny suggestions as to where you could get to try out the switches?