Batthern #324
 Grid  CC BY-SA 3.0

Sometimes simple really is what you need, and this could fit you well.

Source Factorio.us Collective

 More Textures
Prismatic Hypnotic Pattern No Background@2X #572
 Noise  CC 0

Prismatic Hypnotic Pattern No Background

Source GDJ

Lego background #266
 Noise  CC 0

Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.

Source Firkin

Type@2X #277
 Dark  CC BY-SA 3.0

The perfect pattern for all your blogs about type, or type-related matters.

Source Atle Mo

Retro Squares Background 9 #399
 Dark  CC 0

Retro Squares Background 9

Source GDJ

Background pattern 227 (colour 6) #2309
 Red  CC 0

A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.

Source Firkin

Background pattern 302 (colour 2) #1893
 Dark  CC 0

The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.

Source Firkin

Psychedelic Geometric Background No Black #382
 Noise  CC 0

Psychedelic Geometric Background No Black

Source GDJ

Wood Background Pattern #882
 Wood  CC BY-SA 3.0

A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.

Source V. Hartikainen

Prismatic Abstract Geometric Background 5 #401
 Noise  CC 0

Prismatic Abstract Geometric Background 5

Source GDJ