My traffic light simulator is now working. One question, does anyone
know the attribute of a jPanel that I can set to make it flash off and on?

Anyone who wants to see the code can download the jar file from here:

http://sparklesthecat.dnsdojo.org/TrafficLightTest.jar   

I welcome comments and constructive criticsm, but be kind.

Mucho gracias to all those who helped me with this project.