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
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
This one needs to be used in small areas; you can see it repeat.
Source Luca
White circles connecting on a light gray background.
Source Mark Collins
Inspired by an image that was uploaded to Pixabay by geralt
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Groovy Concentric Background 4
Source GDJ
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This is a grid, only it’s noisy. You know. Reminds you of those printed grids you draw on.
Source Vectorpile
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A seamless texture of worn out "cardboard".
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Sharp but soft triangles in light shades of gray.
Source Pixeden