Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Curved Diamond Pattern 8 No Background
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
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
A free seamless background with pink spots.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
I asked Gjermund if he could make a pattern for us – result!
Source Gjermund Gustavsen
Prismatic Polka Dots 3 No Background
Source GDJ
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
This is a remix of "flower seamless pattern".I rotated the original image by 90 degrees.This is a seamless pattern of flowers.These horizontal wavy lines are one of Edo patterns which is called "tatewaku or tachiwaku or 立湧" that represents uprising steam or vapor.
Source Yamachem
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov