Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Black And White Floral Pattern Background Inverse
Source GDJ
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
I asked Gjermund if he could make a pattern for us – result!
Source Gjermund Gustavsen
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
A classic dark tile for a bit of vintage darkness.
Source Listvetra
A pattern derived from repeating unit cells each derived from part of a mosaic in paint.net. The starting point for the mosaic was a picture of some prawns!
Source Firkin
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
emixed from a JPG that was uploaded to Pixabay by Kyotime
Source Firkin
A bit strange this one, but nice at the same time.
Source Diogo Silva
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
An aged paper background tile with smeared and pressed text.
Source V. Hartikainen
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective