There is no blue in the spiral pattern below. Truly.
The Bad Astronomer, Richard Wiseman, and Buzzhunt have all the details.
Go ahead and load it into Photoshop and check the values to see for yourself. The bright color in the blue spiral is identical to the bright color in the green spiral.
The Bad Astronomer (Phil Plait) and Richard Wiseman are regulars at TAM, by the way. They never fail to bring a heaping helping of groovy.