Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Nicely executed tiling for an interesting pattern.
Source Ignasi Àvila Padró
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape 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
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
Prismatic Geometric Pattern Background 2
Source GDJ
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A frame using leaves from an image that was uploaded to Pixabay by mayapujiati
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prepared mostly as a raster in Paint.net and vectorised.
Source Firkin
One more sharp little tile for you. Subtle circles this time.
Source Blunia
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
Prismatic Groovy Concentric Background
Source GDJ
Zero CC plastic pattern texture, photographed and made by me. CC0 *Note, this texture was on the perfectly smooth surface of a plastic shovel scraper, not sure how to call it. Plz coment if you know what its called.
Source Sojan Janso
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
This one has rusty dark brown texture.
Source V. Hartikainen
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim