You could get that pattern with some acrylic paint and a little practice. You could sponge it, but I think a brush would get the pattern better. Put a glob of paint and feather out with a brush. Then spray it with a clear coat and it will hold up okay. Even if it wears, the pattern will hold up. The flakes may look like part of the pattern as well.
The background is the black color of the stock. Either get some gray or black paint. If you start with black paint, you can use it on your practice runs. Paint on cardboard as will stay stiff on you. Add titanium white (a very little at a time) to get to the next lighter shade. A little more for the next, always start will less. White will wash out your darks way too quickly.
There is 3x colors on top of the black stock. It looks like the same color, just lightened. You can find Golden Acrylic paint at Michael's and only need 2x colors (gray or black and white). There is cheaper craft acrylic paint at Walmart as well, but I don't think it'll hold up as well as Golden, which is a museum grade paint. I do watercolor painting as hobby and absolutely could get that pattern with very little effort, but I have always painting and drawing in my blood since a little kid.