hi i had make human make a model and now im getting rid of vertices/ making it so i can uv the clothes right on (no seperate mesh) and i can get the uvs on in the face select but when i exit it goes back to grey anyone know why? 
Did save the .blend file and then import the mesh to another file?
Just using the UV Face Select isn’t enough. Once done, F5 and add a material if you don’t have one already. If you need more than one material you can add them in Edit Mode.
Once you have a material, add a texture in the rightmost panel. Under the “Map Input” tab click the “UV” button. Press F6 and select “Image” as your texture type. In the panel that appears, select your image from the drop-down box (or “Load Image” if there isn’t a drop-down box).
There are other things you can dink with but that’s enough to get the texture to appear.
Hope this helps.