For me, I'd do;
Year 1: A roo over B hens an vice versa.
Year 2: Cross my best crossbreds.
Year 3: Take my second generation and choose my best blue/Blue patterned rooster from the bluest eggs, to cross over Andulusians.
Year 4: Take the year 3 chickens and breed those to my best/bluest year 2...
Start there and keep breeding! You should get mostly, if not all, blue egg layers, because blue is semi-dominant over white (actually way more complicated, but it doesn't matter)
From there, choose your blue, or bluest (you'll likely get some blue-patterned), birds and breed back to a solid...