Are you referring to the instrument panel control dial that controls the light level? If so, there is a control dial (wheel) on the far left of the steering wheel just above the hood release. Roll the wheel until you get the brightness you want.
If you want to turn OFF the Multi-Info. Display screen, press this sequence on the MID: Menu > Display (small icon lower right of screen) > Screen OFF. You can also change the colors, contrast and brightness here also.
Do you have the full manual? It's explained in detail there.
What I am referring to is the blue light that would come on at nights , so that you can see what you are looking for for example to turn the air conditioning on and off and in the entertainment to select the different menu options.