Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Retro Circles Background 4 No Black
Source GDJ
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Black & white version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Groovy Concentric Background
Source GDJ
A textured orange background pattern with vertical stripes.
Source V. Hartikainen
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner