On ebay someone one was selling a set of springs off of an '06 STI recently and they were purple purple front and rear.
slintux, Dead coils per se don't add to to the spring rate all other things being equel. It's the number of active coils.
K=spring rate lb/in
W=wire diameter in
G=120,000,000 for steel
N=number of active coils
D=diameter of the coil at the center of the wire.