Leather 1@2X #14
 Light  CC BY-SA 3.0

A leather pattern with a hint of yellow.

Source Atle Mo

 More Textures
Background pattern 328 (colour 2) #1800
 Green  CC 0

To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i

Source Firkin

3px Tile@2X #343
 Dark  CC BY-SA 3.0

Tiny dark square tiles with varied color tones.

Source Gre3g

Concrete Wall 2@2X #80
 Wall  CC BY-SA 3.0

A light gray wall or floor (you decide) of concrete.

Source Atle Mo

Background pattern 248 (colour) #2180
 Yellow  CC 0

To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Orange Gingham Checkered Background #258
 Stripes  CC 0

From PDP.

Source GDJ

Background pattern 264 #2071
 Orange  CC 0

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

Retro Squares Background@2X #415
 Noise  CC 0

Retro Squares Background

Source GDJ

Tessellation 16 (colour 3) #2213
 Green  CC 0

The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.

Source Firkin

Background pattern 308 (colour 3) #1870
 Colorful  CC 0

Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.

Source Firkin

Diagmonds #336
 Dark  CC BY-SA 3.0

Love the style on this one, very fresh. Diagonal diamond pattern. Get it?

Source INS

"Green Rhombuses", Seamless Background Pattern #1336
 Green  CC BY-SA 3.0

A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.

Source V. Hartikainen

Diamond pattern (colour 9) #2269
 Fabric  CC 0

From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

My Little Plaid@2X #333
 Light  CC BY-SA 3.0

Repeating squares overlapping.

Source Pete Fecteau

Prismatic Curved Diamond Pattern 8 No Background@2X #550
 Dark  CC 0

Prismatic Curved Diamond Pattern 8 No Background

Source GDJ

Background pattern 250 (colour 4) #2168
 Blue  CC 0

To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin