A comeback for you: the popular Escheresque, now in black.
Source Patten
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
A seamless web texture of "green stone".
Source V. Hartikainen
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Prismatic Groovy Concentric Background 2
Source GDJ
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin