The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
Colourful background achieved with gradient fills.
Source Firkin
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
Black And White Floral Pattern Background from PDP.
Source GDJ
Prismatic Groovy Concentric Background No Black
Source GDJ
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Same classic 45-degree pattern, dark version.
Source Luke McDonald
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
A seamless stone-like background for blogs or any other type of websites.
Source V. Hartikainen
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Sort of reminds me of those old house wallpapers.
Source Tish
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin