Please follow these steps: (for products sold after March 2017)
1. Press FN + any key between 1 to 5 on the QWERTY pad of the keyboard (those marked as L1 to L5)
2. Press FN + Home. You will see the NumLock, CapsLock and ScrLock LED indicator on the top right of the keyboard are flashing at the same time
3. Press the key you want to customize multiple times so it changes color every time you press it.
4. When you finished, press FN+Home again to save the setting. The indicators will stop flashing.
5. To switch to a setting you saved, simply press FN + 1 to 5 (L1 to L5)