It probably would revert to another color if it's a hybrid. You never know what you're going to get when you plant seeds of hybrid plants.

If you want to increase your monardas, you don't have to do anything - they will spread all over the place without any help from you. lol!

Monarda astromontana, bradburiana, didyma, x hybrida, and punctata , Sow at 20ºC (68ºF), germ. in less than two wks thin cover, needs light

Monarda citriodora, and fistulosa , Sow at 20ºC (68ºF), if no germination in 3-4 wks, move to -4 to +4ºC (24-39ºF) for 2-4 wks

so thay can be grown from seeds

Yes, they can be grown from seed. But if you have one of the hybrid types, as blueheron mentioned (like those bred for mildew resistance that will still get mildew in my own garden) i.e. Vintage Wine, Commanchee etc...you may get flowers other than those on your parent plant from which you collected your seed.