Psychedelic Geometric Background No Black
Source GDJ
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
Prismatic Abstract Geometric Background 5
Source GDJ
Zero CC asphalt, pavement, texture, photographed and made by me. CC0 WARNING I FOUND A SEAM ON THIS TEXTURE
Source Sojan Janso
Might not be super subtle, but quite original in its form.
Source Alex Smith
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel