As most of you know, colors print less vibrantly on fabric than they appear on computer screens. The hyper-saturated colors in this image are meant to compensate for that, so that you get fabric that doesn't look washed out/dull. This registers as blue on computer screens, but on fabric it is definitely purple.
PLEASE NOTE: This design covers an entire yard. Unfortunately, Spoonflower prints test swatches of only the lower left 8x8 sq. inches of a design, so you will only be getting that little corner (which, as you'll notice, is primarily black background). It doesn't show the true beauty of the stars or the full spectrum of colors.The fat quarter makes a better test swatch, in my humble opinion.