This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
Prismatic Abstract Geometric Background 4
Source GDJ
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
The image is a design of blue glass.How about using it as background image?
Source Yamachem
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Zero CC plastic pattern texture, photographed and made by me. CC0 *Note, this texture was on the perfectly smooth surface of a plastic shovel scraper, not sure how to call it. Plz coment if you know what its called.
Source Sojan Janso
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using 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
Prismatic Abstract Background Design No Black
Source GDJ
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin