There is a pattern called "Giant Vintage Star" posted for free by Jeni Baker. It is only 16 squares, 12 of which are half square triangles. Her tutorial shows it in 2 colors, 4 colors and 8 colors.
http://www.incolororder.com/2011/08/...-tutorial.html I think her blocks are around 17 inches square but resizing should be easy. She uses vintage sheets, hence the name.