Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
The image is a seamless pattern which is derived from a vine .Consequently, the vine got like dots via vectorization.The original vine is here:jp.pinterest.com/pin/500744052301410188/
Source Yamachem
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
An aged paper background tile with smeared and pressed text.
Source V. Hartikainen
A version without colours blended together to give a different look.
Source Firkin
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Dark blue concrete wall with some small dust spots.
Source Atle Mo
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
A seamless pattern based on a tile that can be achieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A pale orange background pattern with glossy groove stripes.
Source V. Hartikainen
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous