Green Gobbler #85
 Dark  CC BY-SA 3.0

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

Source Simon Meek

 More Textures
Prismatic Rounded Squares Grid 3 No Background@2X #490
 Noise  CC 0

Prismatic Rounded Squares Grid 3 No Background

Source GDJ

Prismatic Octagonal Background@2X #440
 Noise  CC 0

Prismatic Octagonal Background

Source GDJ

Retro Squares Background 7 #397
 Noise  CC 0

Retro Squares Background 7

Source GDJ

Green Dust & Scratches@2X #108
 Wall  CC BY-SA 3.0

Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.

Source Atle Mo

Concrete Wall 2 #79
 Wall  CC BY-SA 3.0

A light gray wall or floor (you decide) of concrete.

Source Atle Mo

Wood #49
 Wood  CC BY-SA 3.0

Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.

Source Atle Mo
Based from Cloaks

Background pattern 222 (colour 2) #2344
 Brown  CC 0

A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Circles@2X #186
 Light  CC BY-SA 3.0

One more sharp little tile for you. Subtle circles this time.

Source Blunia

Paper 3@2X #32
 Paper  CC BY-SA 3.0

Light gray paper pattern with small traces of fiber and some dust.

Source Atle Mo

Small Crosses #115
 Stripes  CC BY-SA 3.0

Sharp pixel pattern looking like some sort of fabric.

Source Dmitry

Background pattern 315 (colour 4) #1842
 Colorful  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

Background pattern 259 (colour 6) #2097
 Blue  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

Vintage pattern #2296
 Brown  CC 0

Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

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

Background pattern 225 (colour 4) #2324
 Green  CC 0

Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Carbon Fiber v2@2X #106
 Carbon  CC BY-SA 3.0

One more updated pattern. Not really carbon fiber, but it’s the most popular pattern, so I’ll give you an extra choice.

Source Atle Mo