It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Prismatic Abstract Geometric Background 4
Source GDJ
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
Prismatic Hypnotic Pattern No Background
Source GDJ
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
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
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
This is the remix of "Background pattern 115" uploaded by "Firkin".Thanks.
Source Yamachem
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Prismatic Floral Background No Black
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.
Source V. Hartikainen
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
8 by 8 pixels, and just what the title says.
Source pixilated
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Hypnotic Pattern No Background
Source GDJ
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
The starting point for this was drawn on the web site steamcoded.org/PolyskelionMaker.svg
Source Firkin
A seamless background of warped stripes on paper.
Source V. Hartikainen
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock