/3/ - 3DCG

>>977350
>I thought the different sides of the face were being selected individually
Nah, 3d faces are single sided (kinda) and infinitely thin. Technically, the faces do have a backface that you can access (though it's really just like the inverted normal), but you'd have to do some shader stuff to tell Blender "hey, shade the backface a different color".
If you don't want to do that though, you could just add some thickness with a solidify modifier.