The author Michael Wawra created an application that allows random strangers on the internet to change the color of his Philips Hue light bulbs by sending an SMS message. The application uses Twilio's SMS service and Sinatra, a Ruby web framework, to interact with the Philips Hue API. The application requires a Philips Hue base station, an Ethernet connection, and an IP address to function. To send data to the Philips Hue API, the application sends HTTP PUT requests with JSON data that includes hue, saturation, and brightness values. These values are used to set specific colors for the light bulbs. The application uses Twilio's SMS service to receive messages from users and pass the color value as JSON to the Philips Hue API. Once the code is running on a routable network, users can send an SMS message with a specific hue value to change the color of the light bulb.