Oh yes, it happened! A pattern in full color.
Source Atle Mo
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Retro Circles Background 8 No Black
Source GDJ
Old concrete wall in light shades.
Source Bartosz Kaszubowski
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This is a hot one. Small, sharp and unique.
Source GraphicsWall
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
Retro Circles Background 4 No Black
Source GDJ
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Seamless tile drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev