Here is a vector background of colorful dots, includes a eps file.

Name: Free Vector Colorful Dots Background
Homepage: http://www.webdesignhot.com/
License: Creative Commons Attribution 3.0
File Type: EPS
This image is a vector illustration and can be scaled to any size without loss of resolution. This image will download as a .eps or ai file. You will need a vector editor to use this file (such as Adobe Illustrator).