Make middle grey the default colour in shaders with the diffuse component

As we jumped into the PBR and filmic era long ago, it would be very convenient to have middle grey color in newly created shaders. Now it has the maximum albedo possible, wich is unusable in a vast majority of cases. I propose RGB = 0.214, 0.214, 0.214 or 0, 0, 0.5 in HSV

UPD: I guess it should be 0.18 for middle grey. Don't know why it's 0.214 in blender.