Has anyone tried this? I admittedly haven't done much research. The thought crossed my mind because my daughter crushed one in her hand and now her hand is stained bright yellow.
I've used pollen from the stamens of stargazer lilies, which is a vibrant copper-red. In CP the color came through as a slightly browner but still coppery red color. It did fade very quickly to a dull brown, unfortunately.
Almost everything turns brown when the lye gets to it. Try putting the color into the lye before making the soap and see what happens. Then you can decide to use it or not.