I have a few 3mm color-changing LEDs which I harvested from a toy. They fade in between all different colors, and then after a little while, they blink crazily between all the colors. After a few moments, the cycle repeats.
What is interesting about them (and what I wasn't expecting) is that they only have two leads, like a normal hobbyist LED.
I understand that, like an RGB LED, they have multiple elements (probably not the right word) inside. But how do they achieve the color changing and cycling?
Here is a picture of the LED in question:
Notice the little bit of black material inside the LED. Could this possibly be a tiny chip?