Prismatic Polka Dots Mark II No Background
Source GDJ
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
From a drawing in 'La Principauté de Liège et les Pays-Bas au XVIe siècle', Société des Bibliophiles Liégeois ,1887.
Source Firkin
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
From a drawing in 'Less Black than we're painted', James Payn, 1884.
Source Firkin
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz