Access Vector3 color coordinate inside Cubemap?

Hello I was wondering if the Unity cube map texture allows axis to a 3D coordinate/color within a cube map? I have a cube map that maps the color space in three dimensions and am trying to access colors at specific 3D coordinates within the cube map. Does the cube map create a 3D texture of color or just something mapped to the faces?

 

After some more testing it looks like Cubemap != 3D texture ( I suppose a giveaway was that it allowed 6 sides to be textured )