Each maker had their own (and secret) formula and you can see significant variation in colors among the LCs shown on the PictureTrail. From the following, I'm not sure how Hunter Arms got the lovely 'rose' colors. John Gillette of "Classic Guns Inc." is reported to have the original spec's for L.C. Smiths.
http://www.classicgunsinc.com/ As per Brownells Catalog: Carbon Steel Heat treating
Faint yellow 420 F, Rockwell 63
Light straw 435 F, 62
Dark straw 465 F, 60
Yellow brown 490 F, 58
Purple 520 F, 56
Dark Blue 570 F, 53
Blue gray 620 F, 50