Default Diffuse Texture Profile Issue

I've noticed that across all material maps (whether on shapes or terrain materials), if a diffuse map is not specified, a default diffuse map texture will be applied as an overlay of sorts over all textures. Am I wrong in seeing that it gives off a white hue or tint to the entire material? At least some sort of substance of color that shouldn't be there. It effects the quality of materials I'm using for everything.

Are these assumptions correct? If so, how would I go about removing this? Also, I'm thinking about implementing specular maps to terrain materials. Would this be something that the community would appreciate having or is there no use for it? Or is it already being worked into the next release?