Bought Experienced Breeding Bettas I Think!

Hello after months of preparation I finally bought 4 female bettas! I was looking for a more fancier variety but went into my local store which had very bland colored females which looked stressed! After returning a week later they were still alive and looking still stressed and rather un happy so I decided to rescue them! I thought it would be nice to see them come into colour and give them a nice home! Anyways after settling in I noticed them change to a dark brown whith dark red fins! I'd been doing daily water changes as had noticed one had a damaged scale and feeding them blood worms! On day 4 the dark colour remained and noticed the dark breeding strips! They also looked very plump and notice the tube infront of the anal fin so was definite they all were gravid! So I'm guessing they know well the breeding conditioning! Some times they go back to there true colour and look a little less plump and then they'll plump up and loose slight colour again but always seem to have the tube visible! So basically will they over time realize they're not going to be bred or is there anything I should do?
Also have been feeding them expensive betta food and noticed royal blue at the ends of there fins! There seeming to become more colour full every day despite when they lighten up!

Sorry for the long story! Was interested if any one has had a similar experience or any thoughts suggestions welcome!

Here's some pics anyways! Not great but best I could do!!

What size tank are they in? It looks like they are sharing the same tank, which, I'm learning, is not very good for females in small groups. I'm taking a gamble on a sorority tank, myself, but I am going to be keeping a large group in a twenty gallon long.

It's 15 gallons! They were all bought together and they get on fine other than general chasing off at dinner time! They say more the better but I think it also depends on what temperament the fish u get has! Some are just bullies an the theory is the aggression in this case whould be spread about so not just one fish is being picked on! Smaller numbers works for some but not for all! Mine all get along swimingy and hopefully it remains this way! I am planning on adding more in smaller numbers to see how they get on Good luck with yours!

And from what I've read it pretty much seems to be a gamble for most people when buying groups of these fish! When I was a young girl I purchased two in a 30 litre which they says a definite no no ( oblivious at the time) but again they got along fine and had them for 3 years!!