Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Prismatic Abstract Geometric Background 4
Source GDJ
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
Prismatic Groovy Concentric Background 2
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
Just like your old suit, all striped and smooth.
Source Alex Berkowitz
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green