What rear springs are these?

[turbo87regal]

I was under my parts car today pulling off the factory exhaust hangers for my GNX progect and noticed the rear springs are a light blue color and they are progressive rate. The sticker attached to the spring says install this end down and has the number 64000 on it. Does anyone know who makes springs with this color and with this number I just want to know if its worth my time to swap them onto my other car.

Thanks

 

[SLOWSIXER]

? I had a set of blue ones that were moog