Mix 2 packets of Kool-Aid with 1 cup of white vinegar. ( I think next time I would do 4 packets for the yellow.) Add 2 cups very hot (almost boiling) water and stir in 1 yard of silk. It's amazing how you can literally see the silk drinking up the color.
Once most of the color has been soaked up from the mixture, rinse under cold water, one by one, ringing until it runs clear.