Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
A re-make of the Gradient Squares pattern.
Source Dimitar Karaytchev
Zero CC Mossy stone tileable texture, photographed and made by me. CC0
Source Sojan Janso
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
The perfect pattern for all your blogs about type, or type-related matters.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A white version of the very popular linen pattern.
Source Ant Ekşiler
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Prismatic Hexagonalist Pattern No Background
Source GDJ
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
A seamlessly tileable pink background texture.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
A repeatable image with dark background and metal grid pattern.
Source V. Hartikainen
The image depicts a seamless pattern of a tortoise in tortoiseshell (hexagon).
Source Yamachem
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Prismatic Geometric Tessellation Pattern No Background
Source GDJ