how do you get blue leghorns?

[dtm]

i have black leghorns and white leghorns. if i cross them can i get blue? i read somewhere that some white leghorns carry a blue gene. is this true? and if it is do all white leghorns carry it or just certain ones? i just wondered if i could get a blue leghorn without crossing in the blue from another breed. o and one more thing...how do you all pronounce leghorn?