How can I tell one rear spring weight from another?

[RichMason]

So I yanked the shocks and springs off of my parts car this evening and discovered a beautiful set of Koni shocks with day glo orange springs. I pulled the Bilstiens off of my car (discovering why it rode so low - springs are fine but the spring perches were set at the tightest setting - RR tracks were a nightmare) and I noticed that those springs were black with 3 red dots on a coil about a third of the way up. I have another set of kmart shocks with black springs that I don't believe have any marks on them. Is there anyway to tell which springs are which weight and/or brand?