Tip: What do the colors of the LED light mean?

The indication light, located above the power button, shows the current status of the speaker:
http://download.p4c.philips.com/sca/...5501_95424.JPG

If there is no light from the LED, the speaker is powered off.

If there is light from the LED, Refer to the below for different meanings:

Light	Meaning
http://download.p4c.philips.com/sca/...0208_95427.jpg Blinking amber light	The speaker is starting up.
http://download.p4c.philips.com/sca/...0315_95428.jpg Solid amber light	There is no network connected to the speaker.
http://download.p4c.philips.com/sca/...0349_95429.jpg The light is white and amber alternatively	Non-WPS connection is in progress. Follow the set-up instructions on the App.
http://download.p4c.philips.com/sca/...0421_95430.jpg The light is green and amber alternatively	WPS connection is in progress. Press WPS button on the router; and follow the set-up instructions on the App.
http://download.p4c.philips.com/sca/...0510_95431.jpg Solid white light	The speaker is connected to a Wi-Fi network.
http://download.p4c.philips.com/sca/...0547_95432.jpg Blinking white light	The speaker is muted. Unmute the speaker using the App.
http://download.p4c.philips.com/sca/...0733_95433.jpgSolid green light	The speaker is connected to a Wi-Fi network; and it is in standby mode. The speaker enters standby mode after it has been idled for 30minutes. To switch on the speaker, press power button.
http://download.p4c.philips.com/sca/...0947_95434.jpg Blinking amber light	Firmware upgrade is in progress.
http://download.p4c.philips.com/sca/...1008_95435.jpg Solid red light	There is firmware problem during the firmware upgrade.

LED light is not coherent such as in lasers. It's incoherent just like fluorescents or even incandescents. And no light occurs during reverse bias because there is no electron flow to excite photon activity. IR-type LEDs are just constructed of different materials to take advantage of the resonant properties in that range of frequencies.