If it is simply that you have full range input then the source needs to say it is full range. If it doesn't you can use Crtl-Alt-Shift-I to toggle through the input levels, PC is full range where 255 is mapped to 100% instead of 235. With limited range content you cannot map 236-255 to in-gamut colors; they are, by definition, out of gamut.
Sorry, I am confused as to what you want and why you are looking at this test image.
Please continue to ask calibration questions in the
Display Calibration thread so we don't clog up madshi's thread with calibration.