Mouth only comes up black

I have a figure I made, it has bones, everything, so now I’m working on coloring it, I made a mouth image to go on 2 verts on the face, but for the life of me it refuses to come up anything but black. The image is 16x16 pixels, and nothing. Am I doing something wrong? Also is there a reason it only wants to show my materials in render and not in blender’s object/edit/pose mode?