yes easter egg dyes work feathers and egg shell are made out of the same coligen(as is your hair and finger nails)
Koolaid dyeing: 3 packs of your flavor/color white vinger, dish soap and three containers and a way to heat dye.
1st step wash feathers in warm water w 2 drops dish soap 5min soak.aggitate water (cutting oils in feathers)
2nd container clean water table spoon of vinger 2min soak(getting rid of soap)
3rd place dye in container with water and table spoon of vinger heat(not boiling) add feathers colors will darken with longer time and or adding more dye(koolaid)(may have to reheat) heat puts the dye into the feathers vinger makes it
perminat.
last step rinse in cool water lay flat to dry
cherry red, blue rasberry orange( the two tone was a yellow feathers dipped in cherry red)