Dark Brick Wall #135
 Wall  CC BY-SA 3.0

Black brick wall pattern. Brick your site up!

Source Alex Parker

 More Textures
White Paperboard@2X #375
 Fabric  CC BY-SA 3.0

Could be paper, could be a Polaroid frame – up to you!

Source Chaos

Background pattern 254 (colour) #2143
 Colorful  CC 0

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

Source Firkin

Background pattern 306 (colour 4) #1877
 Colorful  CC 0

Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.

Source Firkin

Background pattern 298 #1899
 Dark  CC 0

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

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

Prismatic Groovy Concentric Background 3@2X #458
 Noise  CC 0

Prismatic Groovy Concentric Background 3

Source GDJ

Diamond pattern (colour 8) #2273
 Red  CC 0

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

Source Firkin

Prismatic Abstract Geometric Background #269
 Noise  CC 0

Prismatic Abstract Geometric Background derived from an image on Pixabay.

Source GDJ

Background pattern 314 #1839
 Yellow  CC 0

The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Mosaic Gems Background #526
 Noise  CC 0

Mosaic Gems Background

Source GDJ