This could be a hippy vintage wallpaper.
Source Tileable Patterns
Prismatic Geometric Pattern Background No Black
Source GDJ
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Here's a tile-able wood background image for use in web design.
Source V. Hartikainen
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Geometric Pattern Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
Prismatic Groovy Concentric Background 4
Source GDJ
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
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Colour version of the original pattern.
Source Firkin
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin