Fabric 1@2X #10
 Light  CC BY-SA 3.0

Semi-light fabric pattern made out of random pixels in shades of gray.

Source Atle Mo

 More Textures
Prismatic Dots Background 2@2X #504
 Noise  CC 0

Prismatic Dots Background 2

Source GDJ

Inflicted@2X #118
 Grid  CC BY-SA 3.0

Dark squares with some virus-looking dots in the grid.

Source Hugo Loning

Background pattern 214 (colour 5) #2374
 Green  CC 0

A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.

Source Firkin

Background pattern 269 #2062
 Dark  CC 0

A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Prismatic Curved Diamond Pattern 4 No Background@2X #542
 Diamond  CC 0

Prismatic Curved Diamond Pattern 4 No Background

Source GDJ

Diagmonds@2X #337
 Dark  CC BY-SA 3.0

Love the style on this one, very fresh. Diagonal diamond pattern. Get it?

Source INS

My Little Plaid #332
 Light  CC BY-SA 3.0

Repeating squares overlapping.

Source Pete Fecteau

Batik Parang Rusak Seamless Pattern(faqeeh)-remix #2450
 Dark  CC 0

As the original image 's page size is too large for its image size, I remixed it.

Source Yamachem

Prismatic Dots Background 8 #515
 Noise  CC 0

Prismatic Dots Background 8

Source GDJ