Intended Paint Effect:
A black base with sporadically placed silver flakes. This will give the illusion of stars and star clusters. The pearl will be the outer layer. Its effect will be a rainbow of colors, ( the colors in the nebula pickguard). This will show when illuminated from the side. So as you move the guitar, the rainbow will move along the edge of the guitar.
This may or may not show in photos, and so a video may have to be taken.