Hi Kara,
I would think that all the DMC floss colors on the list would be needed to cross stitch ALL 6 eggs.
It calls for using DMC floss. Do you already have a "stash" of DMC floss at home? If so, you can save some money by matching up the DMC colors you already own against the floss list for this pattern and then concentrate on buying the DMC floss you are missing.
I'm not an employee of Everything Cross Stitch, just one of the stitchers that comes on the ECS "chat".