I would retain the G19, and sell whichever of the other two is less suited to your needs.
This assumes you carry a weapon---if not, then the Glock might be a good choice just to have commonality of operation.
In my situation, the Sig could do duty as either a backup gun or as a primary carry gun if you need a lower profile, and I would sell the Colt.
Not knowing your situation and needs makes it difficult to make a definitive suggestion here though.
ETA: I do have an anti-.45 bias going on in a way though, as we are not allowed to have one as an off duty or backup gun.*
This *might* have changed with the latest revision, as the new policy puts "if you are carrying a firearm under your authority as an officer of this agency" in bold and underlined type, and no longer has a sentence barring us from carrying under a CC permit or OC without one. Not sure how that works yet with LA statutes governing carry under a CC permit, OC without a permit, or as LE though. Like it or not, if I were to choose to patronize a business with "no guns" signs, they do not legally affect me as LE, per statute, but if I were not LE, and carrying under a CC permit, I could be in violation of the law were I to enter said business. But since state law says I can ignore the signs by virtue of my employment, I am not sure if I would violate policy and/or law by, for instance, strolling into the Circle K on Magazine of a Saturday morning to buy my once a week treat of a fountain Diet Mountain Dew after taking the dog to the levee, as is my wont, while carrying a Springfield 1911 in .45 under my CC permit. (They have a "no guns" sign.)