A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
U.S.-based National Fire Protection Association standard fire diamond for flagging risks posed by hazardous materials. The red diamond has a number 0-4 depending on flammability. The blue diamond has a number 0-4 depending on health hazard. The yellow has a number 0-4 depending on reactivity. the white square has a special notice, e.g OX for oxidizer.
Source Firkin
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This one is amazing, truly original. Go use it!
Source Viahorizon
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
Prismatic Basic Pattern 2 No Background
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 dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Adapted from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Gold Triangular Seamless Pattern No Background
Source GDJ
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
Spice up your next school project with this icon background.
Source Swetha
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
Background pattern originally a PNG drawn in Paint.net
Source Firkin