Blue does not breed true. If hatching 100 chicks from a blue x blue mating, you will get 25% splash, 50% black and 25% black. This type of blue is derived from the Andalusion Blue gene. So if you wanted to breed them and hatch all blue babies, you should do a splash x black cross.
Then there is also Self-Blue, also referred to as lavender by many. This color does breed true, hence why it is called Self-blue. But in cochins, it is still a project underway. I think more folks are working on bantam size self-blue projects. A project means it is a new color variety for the breed, and it is still being worked on, so "type" may not be anywhere near show quality yet, and the variety is not in the SOP yet because it is too new.
HTH!
Oh, you might also note if you are looking for bantam size or LF and you can post a wanted listing in the Buy Sell area.