Background Wall, Art Abstract, Star Well & CC0 texture.
Source Ractapopulous
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
An alternative colour scheme for the original background.
Source Firkin
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
A new one called white wall, not by me this time.
Source Yuji Honzawa
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The base gradient edited so now more details are rendered.
Source Lazur URH
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
A pale olive green background with a seamless texture.
Source V. Hartikainen
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady