The Great Food Coloring Caper

We had a lot of fun at school this week, playing with cause and effect. Food coloring had a part in much of this-like, (1) if we add coloring to the water in a vase and put in a white carnation, what happens? (2)If you add red color at one end of the water in the texture table, and yellow color in the other end, and mix well, what happens to the water?(3) If you have jars of food colored-water, eye droppers, coffee filters, and eight two year olds,what can you make? (5)What happens if the teacher leaves the food coloring on the lower counter?
The answers-(1)the flowers in the blue and yellow waters change colors-for some reason, the red and green vases are slow to share the colors with the flower. (2)You get orange water! (3) Beautiful paper flowers ;-) and (4) a mess on the puzzle table, all the way across the room! You also get four marked plotters, one of whom is caught red-handed…the other three, of course, are blue, yellow and green handed…Which brings me to a question I have always pondered…if red, yellow and blue are chosen for the classic four vial food coloring box because they are the primary colors all other colors are made from, as I assume, who decided to put green in, and why?
How about a nice purple or magenta or chartreuse? Actually, I always need brown and have little luck with mixing the “toast” formula on the back of the box…