Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Prismatic Snowflakes Pattern No Background
Source GDJ
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
Prismatic Groovy Concentric Background No Black
Source GDJ
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A seamless web texture with illustration of pale color stains on canvas.
Source V. Hartikainen
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Looks like an old rug or a computer chip.
Source Patutin Sergey