The Hue series of smart light bulbs by Phillips are multi-color light bulbs you can control from the Hue app over the wireless network. The app is quite flexible and powerful as it allows you to set just about any mood either from presets or custom selection. Basically you can make rooms in your home glow in any color, any brightness for any mood or situation. For example you can set the optimal lighting for concentration or meditation, or you can make them create a funky light show for a party.
A cool alternative to Hue is LiFX, which basically does the same thing in its own way.