I thought this would be neat for my sons science birthday party, a fun goo that all the kids can touch. I was really hoping it would change colors like it said, BUT IT DOESN'T! Very disappointed. I got two tubs, which were smaller than what I thought. One pink and one purple. My son put his in fridge and it just got a bit darker. Put in the microwave and it turned blue. (btw the directions say to do this) But it does not change to the touch like it states! Even the blue now does not want to change back. It does not work at all like a mood ring.