Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Colourful background achieved with gradient fills.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
Prismatic Hexagonalism Pattern No Background
Source GDJ
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. A version of the original with random colors.
Source Firkin
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
You guessed it – looks a bit like cloth.
Source Peax Webdesign
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen