Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.
Source V. Hartikainen
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
Derived from a drawing in 'Historiske Afhandlinger', Adolf Jorgensen, 1898.
Source Firkin
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
Prismatic Floral Background No Black
Source GDJ
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Textured Red Brown Plastic, Free Background Pattern. Although there's already enough plastic in our lives, let's bring it to the web too.)
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek