Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Pattern formed from simple shapes. Black version.
Source Firkin
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
Black And White Floral Pattern Background Inverse
Source GDJ
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
Can’t believe we don’t have this in the collection already! Slick woven pattern with crisp details.
Source Max Rudberg
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
Same classic 45-degree pattern, dark version.
Source Luke McDonald
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.
Source V. Hartikainen
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin