Background pattern 19 (outline) #204
 Light  CC 0

A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.

Source Firkin

 More Textures
Connected #348
 Light  CC BY-SA 3.0

White circles connecting on a light gray background.

Source Mark Collins

Background pattern 252 (colour 4) #2159
 Light  CC 0

Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Prismatic Polka Dots Mark II 2 No Background #532
 Noise  CC 0

Prismatic Polka Dots Mark II 2 No Background

Source GDJ

Background pattern 215 (colour 2) #2370
 Blue  CC 0

A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.

Source Firkin

Background pattern 236 #2249
 Dark  CC 0

Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

A dark wool background pattern with diagonal stripes #907
 Stripes  CC BY-SA 3.0

Feel free to download and use it, or see the rest of the dark background patterns that I have made. Anyway, I hope you will find something that you like.

Source V. Hartikainen

Retro Squares Background 6 #396
 Noise  CC 0

Retro Squares Background 6

Source GDJ

Elastoplast #282
 Light  CC BY-SA 3.0

A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.

Source Josh Green

Merely Cubed #589
 Grid  CC BY-SA 3.0

Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.

Source Etienne Rallion

gourd seamless pattern #2277
 Brown  CC 0

The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.

Source Yamachem

lotus crane #2499
 Concrete  CC 0

The image depicts a seamless pattern of the design which includes a stylized lotus and a stylized crane.I referred to the original image in a book which is into public domain.

Source Yamachem

Background pattern 263 #2073
 Pink  CC 0

Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.

Source Firkin

Diamond pattern (colour 7) #2274
 Red  CC 0

From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin