This is my first post and first project. It worked! Thanks Adafruit!
One of my goals when picking up this hobby was to contribute things to the community once I gained enough knowledge to have something useful to share. Not easy when you're just starting out and know practically nothing, but here goes.
When I finished the soldering and ran the first test I noticed that I could see one and only one of the purple LEDs lighting up. It was (and still is) visible to the naked eye. I then tried to use my iPhone 6 camera to see if the others were blinking. They did not show up. After a quick scan of this forum I learned that some digital cameras filter IR. I repeated the test with the iSight camera in my ancient iMac. Success! All four LEDs blinked brightly. It also works to turn off my TV. :)
Conclusion: The camera in the iPhone 6 has an IR filter that doesn't allow you to see the IR LEDs blinking. Use something else for your tests.
Question: Why is the light from one of the LEDs visible to the naked eye?