I didn't like the blue lemonade, so I added the strawberry for a mauve result. The blue lemonade was too light, and the lemon aspect of it probably compromised the depth of color. Will probably resort to acid dyes for real blue yarn in the future, though I have no intention of ever knitting a Tardis garment, ever. Never.
This was very fun and I recommend it as a non-toxic activity for kids. Middle child enjoyed it. As the yarn soaks in the Kool-Aid solution the water turns clear as if by magic. It must be wool or other protein fiber to work.
Under the Desk has very thorough directions. There are also several YouTubes of the process out there.