Thanks for the good idea, FrogDog! I think you are right.
Guess what? I was shopping at my nearby grocery store yesterday. I had thought I'd have to either buy the sheets or wait until Halloweentime to find the ready-made black confetti. I'd called everywhere, and they all said they have it only at Halloween.
But my shopping partner spotted this grocery store generic brand of cake confetti, at not a bad price, on sale, even, called "Robots," and it contains the black! Yippee!!!! Less work for me. There is also hot green, fluorescent purple, & bright blue confetti in the mix, and I think they would be fun to decorate the eggs with, too, for a variety of ladybug spot colors. I think children would enjoy making ladybugs with different colored spots. The blue and purple would look good on the yellow yolks. I am so excited to have found some of the black confetti at last. I hadn't thought my grocery store, which has a small cake decorating section would have them!