Dark Wall #817
Dark CC BY-SA 3.0Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
More Textures
Stacked Circles@2X #674
Light CC BY-SA 3.0A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Background pattern 261 #2076
Dark CC 0Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
Rough Concrete Surface #1195
Concrete CC BY-SA 3.0This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
Fake Luxury@2X #622
Diamond CC BY-SA 3.0Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Subtle Stripes #751
Stripes CC BY-SA 3.0Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Diagonal Striped Brick@2X #680
Stripes CC BY-SA 3.0Might not be super subtle, but quite original in its form.
Source Alex Smith
GPlay@2X #736
Light CC BY-SA 3.0A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
A dark wool background pattern with diagonal stripes #907
Stripes CC BY-SA 3.0Feel 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
"Gold Buttons", Pale Yellow BG Pattern #1215
Yellow CC BY-SA 3.0This yellow background consists of a pattern of glossy gold buttons arranged in polka dot style on a seamless texture. Here's a pale yellow background pattern. Feel free to use it for your needs!
Source V. Hartikainen
Connected@2X #349
Light CC BY-SA 3.0White circles connecting on a light gray background.
Source Mark Collins
Background pattern 309 #1866
Yellow CC 0Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Farmer #659
Fabric CC BY-SA 3.0Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Tex2res3 #723
Fabric CC BY-SA 3.0Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Stylized lion design #2089
Dark CC 0Derived from a drawing in 'Historiske Afhandlinger', Adolf Jorgensen, 1898.
Source Firkin
Background pattern 328 (colour 4) #1798
Green CC 0To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
"Polished Blue Stone", Seamless Web Texture #1052
Stone CC BY-SA 3.0An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
Floral background 10 (colour 2) #2045
Pink CC 0Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
Subtle White Feathers@2X #1104
Light CC BY-SA 3.0This one is amazing, truly original. Go use it!
Source Viahorizon
Sine wave background 2 #1734
Dark CC 0The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin