The border can be any colour with white or clear being usually just butterfly, and with bicolour banded fins being 'self butterfly' or sometimes just butterfly. White or clear is preferred in most intentional butterfly lines (where the butterfly marking is being bred in) but it often occurs incidentally while breeding for something else and that's when you're likely to get sbf (mixture of two solid colours in bands on the fins). Where there are three or more bands on the fins it's a multicolour.
The appropriate females to use would depend on what you're trying to breed. There are so many ways you can combine betta pairings. Like, I could have a female from a completely different SD line and want to enhance the fins, so breed her to one of those and then choose the fry that had her colours to breed next. If you want to copy their colours, use the female with the closest colours you can find. For the last male, blue iridescence on red is dominant, so if you bred to a red female you would probably still be seeing the blue scales on the body and the red in the fins. For the second, IMO a copper or a black female would make a stunning match, or maybe a pink or light red. For the first, MG females are not always easy to find (and usually expensive). Failing a true MG look for anything with yellow in it, because the black base colour and blue iridescence are dominant and will probably carry down to at least some of the fry. Look for a female with yellow and you will probably also get yellow markings on some of the fry, and with any luck some will be true MG.
Hope this helps.