Prismatic Abstract Line Art Pattern Background 2 #567
 Dark  CC 0

Prismatic Abstract Line Art Pattern Background 2

Source GDJ

 More Textures
Prismatic Polka Dots Mark II No Background #530
 Noise  CC 0

Prismatic Polka Dots Mark II No Background

Source GDJ

Retro Circles Background 4 #420
 Dark  CC 0

Retro Circles Background 4

Source GDJ

Soft Kill@2X #319
 Dark  CC BY-SA 3.0

Pattern #100! A black classic knit-looking pattern.

Source Factorio.us Collective

White Plaster@2X #369
 Wall  CC BY-SA 3.0

Sweet and subtle white plaster with hints of noise and grunge.

Source Phil Maurer

Colorful Floral Background 2 #487
 Dark  CC 0

Colorful Floral Background 2

Source GDJ

Background pattern 259 (colour 3) #2130
 Colorful  CC 0

Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Background pattern 264 #2071
 Orange  CC 0

The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Background pattern 238 #2229
 Red  CC 0

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

Source Firkin

Background pattern 315 (colour 5) #1841
 Yellow  CC 0

The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Prismatic Chevrons Pattern 5 With Background@2X #470
 Dark  CC 0

Prismatic Chevrons Pattern 5 With Background

Source GDJ

Background pattern 6 #225
 Noise  CC 0

Another fairly simple design drawn in Paint.net and vectorized in Inkscape.

Source Firkin

Retro Squares Background@2X #415
 Noise  CC 0

Retro Squares Background

Source GDJ