Post some good pictures once you get them, will help us get an idea where they could use some help, type wise. Which is an area most new project colors really need some help. Putting a good light male over blue columbian females should produce 50% blue columbian, and 50% (black trimmed) lights.
Now what will be interesting is to see if there is any affect on the green sheen of the black feathers on the lights from this cross. I have heard old stories that blacks that come of blue breeding sometimes lose the beetle green sheen on the males. Really doesn't affect your project here, as you are breeding for blue, but still would be interesting to note. I put a good light male over splash columbian females, there by getting all blue chicks, but did not get a chance to test that theory when the coyote nabbed the blue cockerel.
Really this should be an easy project to bring up to snuff, as all you will be doing is adding blue to an established variety, which just happens to have the best type and size of the current Brahma varieties. You could keep the best blue chicks each year, breed them to top noch lights, for as many generations as it takes to get the type off the blues on par with the best lights. So much easier than breeding toward a different pattern.