An autoaction to finish up cell shading and make it look smoother.
1. Select the layer with shading

2. Choose the color you want to be the "in-between" color.
The first pop-up window: thickness of the middle line
Second pop up window: blur of the inner line within the shadow
Third and fourth (same size recommended): blur of the whole shade
3. Adjust the corners with smooth ereaser if needed
