Subtle Freckles@2X #90
 Light  CC BY-SA 3.0

This is so subtle: We’re talking 1% opacity. Get your squint on!

Source Atle Mo

 More Textures
Background pattern 4 #223
 Noise  CC 0

A pattern derived from repeating unit cells each derived from part of a mosaic in paint.net. The starting point for the mosaic was a picture of some prawns!

Source Firkin

Concrete Wall@2X #78
 Wall  CC BY-SA 3.0

Dark blue concrete wall with some small dust spots.

Source Atle Mo

Snowflake remix #155
 Dark  CC 0

A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.

Source Lazur URH

Cross Stripes #47
 Dark  CC BY-SA 3.0

Nice and simple crossed lines in dark gray tones.

Source Stefan Aleksić

Polonez Pattern #334
 Gray  CC BY-SA 3.0

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

Source Radosław Rzepecki

Background pattern 208 #2465
 Grid  CC 0

A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Abstract Ellipses Background Grayscale #378
 Dark  CC 0

Abstract Ellipses Background Grayscale

Source GDJ

Background pattern 214 (colour 6) #2372
 Colorful  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

Abstract Arbitrary Geometric Background@2X #498
 Noise  CC 0

Abstract Arbitrary Geometric Background derived from an image on Pixabay.

Source GDJ

Green Gobbler@2X #86
 Dark  CC BY-SA 3.0

Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.

Source Simon Meek

Prismatic Curved Diamond Pattern 6 No Background@2X #546
 Dark  CC 0

Prismatic Curved Diamond Pattern 6 No Background

Source GDJ

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

Squares@2X #303
 Dark  CC BY-SA 3.0

Dark, square, clean and tidy. What more can you ask for?

Source Jaromír Kavan

Leather 1@2X #14
 Light  CC BY-SA 3.0

A leather pattern with a hint of yellow.

Source Atle Mo

Prismatic Groovy Concentric Background 5 No Black #467
 Dark  CC 0

Prismatic Groovy Concentric Background 5 No Black

Source GDJ

Seamless Core Pattern 10 #171
 Dark  CC 0

Seamless Core Pattern 10

Source GDJ