To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Alternative colour scheme to the original.
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Prismatic Abstract Background Design No Black
Source GDJ
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo