So, took a bit of a break from the reno for Christmas...
I also started a wee DIY project to paint the screens for the in-wall speakers. I tried doing research on this topic, but didn't find that much in the way of instructions, so I cobbled together bits and pieces of tips and tricks and started my journey.
Here's the tools I used:

A basic airbrush from Michael's Crafts, a can of CO2 (Propel), spoons for getting paint into that tiny jar, toothpicks for poking out oversprayed holes, an N95 mask, a multi-tool, some paint and water (not pictured), and paper towel.

First thing I had to do was remove the felt on the inside of the screens:


Then I mixed the paint about 2/3 water to 1/3 paint and got to spraying. Fairly easy to apply, but hard to get even on the first coat. I had some overspray so I went at the holes with a toothpick, but found that "dabbing" the oversprayed areas with paper towel did a better job of removing the clogs. It also removed some of the paint, though. You can see where I did some wiping in the middle screen.
Here's after 1 coat:

And after the 2nd coat (which I sprayed in the opposite direction of the 1st coat):

It's coming along, but it will likely take 4-6 coats to get it even. 3rd coat will go on in about an hour.