I bought several Color Changing Solar LED sidewalk lights at Walmart. Of
the four I bought, three of them changed color, the 4th one stayed red
all the time. Since I was going to Walmart, I took the defective one and
exchanged it yesterday for one that works properly.

I'm only posting this because I opened it up before I returned it, and I
could not see any circuit board, chips or other parts. Just the LED and
some wires going to the battery and solar panel. This makes me wonder
how they change color???? Apparently the whole circuit is built right
into the LED itself. Anyone know anything about them?