Background pattern 250 (colour) #2171
 Yellow  CC 0

To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

 More Textures
Background pattern 238 (colour 2) #2228
 Green  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Background pattern 9 (greyscale) #213
 Dark  CC BY-SA 3.0

Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net

Source Firkin

Carbon Fiber@2X #4
 Carbon  CC BY-SA 3.0

A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.

Source Atle Mo

Prismatic Abstract Geometric Background 2 No Black #445
 Noise  CC 0

Prismatic Abstract Geometric Background 2 No Black

Source GDJ

Project Papper@2X #120
 Paper  CC BY-SA 3.0

Light square grid pattern, great for a “DIY projects” sort of website, maybe?

Source Rafael Almeida

Carbon Fiber v2 #105
 Carbon  CC BY-SA 3.0

One more updated pattern. Not really carbon fiber, but it’s the most popular pattern, so I’ll give you an extra choice.

Source Atle Mo

Background pattern 26 (black) #199
 Dark  CC 0

Pattern formed from simple shapes. Black version.

Source Firkin

Floral Pattern Background 5 #219
 Noise  CC 0

PDP

Source GDJ

crissXcross@2X #112
 Dark  CC BY-SA 3.0

Dark pattern with some nice diagonal stitched lines crossing over.

Source Ashton

Retro Circles Background 6@2X #429
 Noise  CC 0

Retro Circles Background 6

Source GDJ