Is there a way to draw something within the UV viewport and not the 3d viewport?
In Uv Editor switch the Mode to Paint. Open a Tools panel (T) and select a brush.
Now you can paint. Remember to save your image when you're done with painting (Image-->Save As Image). When you see a little star (*) next to the Image in header it means that the image isn't saved.
Here are some useful shortcuts that can be used in a UV Editor window:
- press S to pick a color sample
- hold S and press LMB to add a color sample to your palette (you may also do it pressing a + button located under the circular color palette).
- press F to change the size of a brush
- press Shift+F to change the strenght of a brush
After pressing the shortcuts you may also change the attributes of a brush using numerical keyboard buttons.
- press E to change the stroke method
Here you can find many interesting options (like a Curve stroke- very useful for precise painting).
- press X to quickly flip the color slots