If you want indicator solutions, cabbage juice is a good one.
Get a head of fresh, red cabbage. Shred it up as if you want to make cole slaw.
Put your shredded cabbage in a pot of water and boil it for 15 or 20 minutes.
Strain off the liquid. It will be reddish purple.
Changes in pH will cause the anthocyanin pigment in the cabbage juice to change color.
pH 2 = Red.
pH 4 = Purple.
pH 6 = Violet.
pH 8 = Blue.
pH 10 = Blue-Green.
pH 12 = Yellow-Green.
There is a community organization in my town that used to have Harry Potter days during the summer where kids would come together and play magical games and stuff. I was a volunteer and I got to be the "Snape." (The potions teacher.) The cabbage juice trick is one of the things I did for the kids.