Material Shader not fully applied to selected faces? Why? I am adding materials to my model but the bottom edges of faces do not show the colour/material even if the rest of its faces are coloured. Why is this?

As you can see by the picture, the grey area above the indent is part of the face of the red material but it is not shaded red along with the rest of the face. The indented section only coloured the middle red and left the top and bottom material-less. How do I fix this?
When you have more than one material on your object, usually you only have to select the faces you want to color and then press “Assign” in the material property panel. 
Logically, you have the right (red) material in the list selected.
You can see every function you need on your screenshot.

Did that not work for you?