This is a free tool to generate 300 dpi square pattern image from a 5 colors palette.
Setting the number of pixels per inch gives you a print size of your image on the screen.
You can save and load your palettes and configuration.
You could use the Colourlovers website to choose a palette http://www.colourlovers.com/palettes
If you have any questions email me at firstname.lastname@example.org