First check the HCI device is up and running
sudo hciconfig
hci0: Type: BR/EDR Bus: USB BD Address: 00:1A:7D:DA:71:08 ACL MTU: 310:10 SCO MTU: 64:8 UP RUNNING PSCAN RX bytes:80815 acl:0 sco:0 events:2559 errors:0 TX bytes:1372 acl:5 sco:0 commands:83 errors:0
If the device is showing like this you are good to go. When it is showing as DOWN, you can bring it up with
sudo hciconfig hci0 up
Let's start a scan for LE devices
sudo hcitool lescan
AC:E6:4B:06:2C:55 PLAYBULB CANDLE AC:E6:4B:06:66:9A (unknown) AC:E6:4B:06:66:9A PLAYBULB CANDLE
You have to kill it with CTRL+C
Now you can use the Device MAC and set a new color or effect The following command will set the color to green
gatttool -b AC:E6:4B:06:2C:55 --char-write -a 0x0016 -n 0000ff00
The next command will set the the effect to flash, and color to red
gatttool -b AC:E6:4B:06:2C:55 --char-write -a 0x0014 -n 00ff000000001f00