I wanted to make a simple tiled background image for this one. This used to be a common thing but has fallen out of favor.
I used this image by cogdog as the basis of my work, then I imported it into my graphics editor. From here, I was able to shrink it to 600 pixels in width, add a tiling effect (Filters > Map > Tile Seamless) before messing with the color and brightness. The result is an 84kb PNG file.