Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
Seamless Prismatic Geometric Pattern With Background
Source GDJ
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
A seamless background colored in pale orange. It has a paper like texture with diagonal grid pattern.
Source V. Hartikainen
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Alternative colour scheme for the original floral pattern.
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova