Ambient light not reflecting right

I am programming an Ambient Light Shader. In the Material Block i stablish the Ambient Color to White.

 Material
 {
    Ambient[_Color]
 }

Of COurse the _Color Property is white and my render setting ambient color is white. But my Object in the game keeps drawing in a gray-like color. Why is it that? if in documentation says the resulting color is:

Ambient RenderSettings ambient setting + (Light Color Diffuse + Light Color * Specular) + Emission

I don't have Diffuse nor Specular nor Emission Color, so the Equation should be

(1) * (1) + ((0) + (0)) + (0) = (1)

WHITE!! but my object is gray. Am i doing something wrong? or that is the normal behaviour of ambient light.