Purple Colored Valve Springs?

Trying to determine what spring you have base on color is about the stupidest method in the world. The best (and only) way is to measure their installed height, remove them and measure their pressure at that installed height.
Nobody is trying to figure out spring rates. This is just the mystery of the purple springs, as I’ve never seen any spring like this. If I wanted to figure out rates I’d check installed height and then check pressure at installed to coil bind. I have a comp setup right in on my bench. These don’t look hardened they are much different but it’s hard to pick up on camera.