A gas turbine blade 10 comprises a base metal, a platform 14, an airfoil 12 extending upwardly from the platform, a shank 18 extending downwardly from the platform. The shank has an exterior wall 71 and an internal passage 84, and the airfoil 12 has a cooling flow channel 34 inside the airfoil for flowing a cooling flow therethrough. The blade has a first chromide coating 102 contacting the base metal of at least a portion of an interior surface of the shank 18 and interdiffused therewith, wherein the first chromide coating does not have an aluminide coating deposited over it. The blade has a second chromide coating 144 contacting the base metal of at least a portion of an interior surface of the airfoil 12 and interdiffused therewith. A method 200 for preparing a gas turbine blade comprises the steps of applying chromide coatings 71, 72, 73, 74, sealing the interior passages 80 of the shank and airfoil and applying 82, 84 an aluminide or platinum aluminide coating and an optional ceramic layer 86 on the airfoil.