2) Remember, now is the time to stock up on a year's supply of
"egg" dyes. Today they are half price or so ... and soon they
won't be conveniently available at any price until next year.
It's nice to have some on hand. They don't spoil. There's lots
of good experiments to do with dyes; the physics of dyes is
nontrivial, and students (not to mention grownups) have many
misconceptions about it.
I'm partial to the Paas 9-color kits. (Paas also makes a 6-color
kit, which is easier to find but not as nice. Many competing kits
have only 5 colors.) It's inconvenient to get 9 different colors
of food dye at any other time of year.
Using food-grade dyes has advantages in terms of safety.