The following repeating website background is colored in a blue gray color and resembles a concrete wall or something similar to it.
Source V. Hartikainen
A free seamless background pattern for use on websites.
Source V. Hartikainen
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
This is the remix of "Tileable Wave Pattern 2" uploaded by "Arvin61r58".Thanks.I added a wire-mesh fence seamless pattern as a lower layer.
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
Lovely pattern with splattered vintage speckles.
Source David Pomfret
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Dark blue concrete wall with some small dust spots.
Source Atle Mo
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin