Add patterns as an overlay option in addition to colors and gradients

[jasmussen]

The Cover block lets you choose between color and gradient for the overlay:

Extending that to allow the use of a pattern can potentially open up some stylish expressions, perhaps especially when applied to video. Shown here, a pixel grid overlay:

The existing color picker could be extended to surface these patterns as a tab, just like gradients:

The patterns themselves can be entirely CSS based, here's a codepen with an example.