Hmmm...what do you mean fixed it? (I know you said why but I'm not understanding...you mean the link to the pic?)
For the diamond interior...you said a simple star...but how to get 4 "quadrants" at different shades?
What if...masking 1/2 of the diamond, and then paint (get you 1/2 light, 1/2 dark), then rotate the mask 90deg and paint the same shade. Would this result in one really dark quadrant, and then the two opposite quadrants medium, and one remaining quadrant unpainted (light)...
?
Somehow, though, the middle has white lines, as well. Maybe "do a star" in white will do this...
Am I overthinking it?
THANKS