MSI Gaming Center can be used to control the lighting effects of the GK40 keyboard. If you do not wish to use the function keys to change your setting from the keyboard itself.
Once you have installed the MSI Gaming Center software it is best to select the Reset button in the lower right of the screen to update keyboards programming. Then from there, you can select the GK40 to see the rest of the options.
This page has eight different lighting options along with the direction, brightness, and selected color.
If you choose profile option you have the ability to select each regions color and the brightness of the overall keyboard.