Brushed Alum Dark@2X #66
 Dark  CC BY-SA 3.0

Because I love dark patterns, here is Brushed Alum in a dark coating.

Source Tim Ward

 More Textures
Patchwork Quilt Pattern Background #228
 Noise  CC 0

PDP

Source GDJ

Shapes pattern #2409
 Brown  CC 0

A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Prismatic Groovy Concentric Background No Black@2X #452
 Noise  CC 0

Prismatic Groovy Concentric Background No Black

Source GDJ

Background pattern 251 (colour 5) #2163
 Red  CC 0

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

Source Firkin

Prismatic Dots Background 3@2X #506
 Noise  CC 0

Prismatic Dots Background 3

Source GDJ

Background pattern 117 #524
 Noise  CC 0

A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.

Source Firkin