Each light and indicator on this headset has its own story, the trick is learning the language! Here we will break it down so you can learn to speak the same language as your wireless headset.
On the Headset

SOLID BLUE: Headset is charging on the base (this light may go away if the headset is fully charged)
RED/BLUE FLASH: Headset is being paired to the base.
3 BLUE FLASHES: Headset is turning on OR headset is successfully connected to the base.
3 RED FLASHES: Headset is turning off.
BLUE QUICK FLASHING: A call is coming in.
SOLID RED: Headset is on an active telephone call OR Supported Softphone Status: Busy
PURPLE CONSTANT: Streaming Music
NO LIGHT: Headset is fully charged when sitting on base OR headset is off when not on the base.
BLUE/RED/PURPLE/BLUE FLASHING: Firmware Upgrade in progress
On the Base

Let’s take this from left to right!
RED above the Mute (radio microphone with a slash) icon: Mute is ON. No light of course means the headset is not muted.
WHITE above Computer, Telephone, or Smartphone icon: Mode is on. The white button lets you know what device will turn on if you tap the headset to answer or start a call. If you’d like to change modes, just tap a different one of these three buttons.
BLUE CONSTANT above Computer, Telephone, or Smartphone icon: The headset is turned on (it's like the blue diamond on the OfficeRunner)
BLUE Constant over two different icons: A merged call between two modes is in progress. Both modes’ LED lights will turn blue when they are merged together on an active call.
BLUE QUICK FLASHING above Computer, Telephone, or Smartphone icon: Incoming Call
BLUE SLOW FLASHING above Computer, Telephone, or Smartphone icon: Call on hold.
WHITE above the Accessory (star) icon: USB headset is plugged in OR Bluetooth headset is connected via the dongle.
RED CONSTANT: No Headset is connected to the base.
RED FLASHING: Incoming call with no headset connected to the base OR the connected USB headset is not supported.
PURPLE CONSTANT above the accessory (star) icon: Streaming Music
GREEN CONSTANT: Dictation Mode is on
Battery Lights
4 WHITE Battery Lights: Battery is at 100%
3 WHITE Battery lights: Battery is at 75%
2 WHITE Battery lights: Battery is at 50%
1 WHITE Battery light: Battery is at 25%
1 FLASHING WHITE Battery Light: Battery needs to be charged.
On the Dongle (photo at top)
BLUE/RED FLASHING QUICKLY: Dongle is pairing to a device
BLUE/RED FLASHING VERY QUICKLY: Dongle is pairing to a 2nd Bluetooth Sennheiser headset
3 BLUE FLASHES: Pairing successful
3 RED FLASHES: Pairing failed
BLUE FLASHING: Dongle is connecting to a device.
FAINT BLUE CONSTANT: Dongle and Bluetooth Device Connected
BRIGHT BLUE CONSTANT: Outgoing/active call
BLUE FLASHING QUICKLY: Incoming Smartphone call
PURPLE CONSTANT: Music Streaming
RED FLASHING CONSTANT: Bluetooth device is muted.