That’s correct about the red / brown / blue.
For your keyboard there’s no major difference between 3-pin and 5-pin switches, but for other keyboards (or rather the PCBs within other keyboards) it does matter. You can use a 3-pin switch on a 5-pin PCB, but you can’t use a 5-pin switch on a 3-pin PCB (technically you can clip off 2 plastic pins on a 5-pin switch and it would work with a 3-pin PCB).
The 5-pin switches do offer extra stability versus 3-pin switches, but it’s not a big difference.
The most important part of picking a switch is deciding your favorite between linear vs tactile vs clicky, then narrowing down based on other factors like spring weight and mushiness. You can do that through trial and error or by looking up reviews / information about switches. I still recommend getting a switch tester / sampler, but you can also check out ThereminGoat’s reviews at: https://github.com/ThereminGoat/switch-scores.
They’re trying to command you to either provide an example of them being “incredibly rude” to someone helping them or delete your comment. This person feels like a caricature of an internet dweller, it’s pretty great.