Prismatic Chevrons Pattern 5 With Background #469
 Dark  CC 0

Prismatic Chevrons Pattern 5 With Background

Source GDJ

 More Textures
Visual illusion #2586
 Grid  CC 0

The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Prismatic Abstract Geometric Background 3 #270
 Noise  CC BY-SA 3.0

Prismatic Abstract Geometric Background 3

Source GDJ

Background pattern 308 (colour 3) #1870
 Colorful  CC 0

Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.

Source Firkin

Background pattern 265 #2081
 Dark  CC 0

Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Colorful Floral Background@2X #480
 Noise  CC 0

Colorful Floral Background

Source GDJ

Dark Circles #306
 Dark  CC BY-SA 3.0

People seem to enjoy dark patterns, so here is one with some circles.

Source Atle Mo

Background pattern 215 (colour 4) #2368
 Green  CC 0

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

Source Firkin

Greek key pattern 5 #2294
 Dark  CC 0

Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.

Source Firkin

Pool Table #175
 Wall  CC BY-SA 3.0

This makes me wanna shoot some pool! Sweet green pool table pattern.

Source Caveman

Polonez Pattern #334
 Gray  CC BY-SA 3.0

A car pattern?! Can it be subtle? I say yes!

Source Radosław Rzepecki

Pinstripe@2X #36
 Light  CC BY-SA 3.0

Light gray pattern with a thin pinstripe.

Source Brandon

Prismatic Geometric Pattern Variation 2 With Background #471
 Noise  CC 0

Prismatic Geometric Pattern Variation 2 With Background

Source GDJ