I just hung this pretty trip around the world crib quilt in my living room, using a vintage yard stick. Remember that post? In this "rainbow" variation, there are four different fabrics of each color, blue, red, green, and yellow. Not exactly ROYGBIV, but you get the idea.
This is a Pennsylvania quilt that dates to around 1880-1900. It is 28" square. The back is made up of two different calicos.