Feel free to download and use it, or see the rest of the dark background patterns that I have made. Anyway, I hope you will find something that you like.
Source V. Hartikainen
The original enhanced with some gradients.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Embossed lines and squares with subtle highlights.
Source Alex Parker
Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
Embossed lines and squares with subtle highlights.
Source Alex Parker
Seamless Prismatic Geometric Pattern With Background
Source GDJ
White circles connecting on a light gray background.
Source Mark Collins
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Prismatic Groovy Concentric Background 2
Source GDJ
A repeating graphic with ancient pattern. I came up with this name/title at last minute, so you may find that there is very little of ancientness in this pattern after all.
Source V. Hartikainen
Dark blue concrete wall with some small dust spots.
Source Atle Mo
A seamless background tile of aged paper with shabby look.
Source V. Hartikainen
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.
Source V. Hartikainen
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning