Lastchance,

I agree with Scott, you wont be able to dye the black feathers into olive. When it comes to using Kool-Aid, make sure you use the sugar-free kind if not you will end up with a sticky mess. For natural colors (olives, duns, browns) I prefer to use Veniards. For blues, greens, reds, etc, you can't beat some Kool-Aid. Using vinegar is important to set the color.

Regards,

Alberto