Background pattern 223 (colour 6) #2348
 Yellow  CC 0

Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

 More Textures
"Polished Stone", Gray Background Pattern #1053
 Stone  CC BY-SA 3.0

A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).

Source V. Hartikainen

Heart and rose pattern #2419
 Pink  CC 0

Seamless pattern formed from a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.

Source Firkin

Prismatic Abstract Line Art Pattern Background@2X #566
 Dark  CC 0

Prismatic Abstract Line Art Pattern Background

Source GDJ

Groovepaper #577
 Paper  CC BY-SA 3.0

With a name like this, it has to be hot. Diagonal lines in light shades.

Source Isaac

Tessellation 15 (colour 2) #2221
 Yellow  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 18 #202
 Dark  CC 0

A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.

Source Firkin