Always Grey@2X #54
 Dark  CC BY-SA 3.0

Crossing lines with a subtle emboss effect on a dark background.

Source Stefan Aleksić

 More Textures
Floral design 100 (version 2, colour) #1772
 Green  CC 0

From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.

Source Firkin

Patchwork Quilt Pattern Background #228
 Noise  CC 0

PDP

Source GDJ

Prismatic Isometric Cube Extra Pattern No Background #405
 Light  CC 0

Prismatic Isometric Cube Extra Pattern No Background

Source GDJ

Fire diamond #2488
 Diamond  CC 0

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

Dark Stripes #39
 Dark  CC BY-SA 3.0

Very dark pattern with some noise and 45-degree lines.

Source Stefan Aleksić

Connected@2X #349
 Light  CC BY-SA 3.0

White circles connecting on a light gray background.

Source Mark Collins

Black Mamba@2X #58
 Dark  CC BY-SA 3.0

The name alone is awesome, but so is this sweet dark pattern.

Source Federica Pelzel

Spirals pattern #1994
 Colorful  CC 0

Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i

Source Firkin

Retro Squares Background@2X #415
 Noise  CC 0

Retro Squares Background

Source GDJ

Prismatic Groovy Concentric Background 5 No Black@2X #468
 Dark  CC 0

Prismatic Groovy Concentric Background 5 No Black

Source GDJ