The c6 is a rbg meter it does not have a yellow censor in it.. you can nit adjust color space on a quatron
Your eye doesn't have a yellow sensor either.
We have tri-chromatic vision, our entire system of measuring and quantifying color is based around the fact that our eye has short, medium and long wave cones that roughly equate to blue, green and red colors. Everything we perceive is based on the sensitivity of those cones. Yellow is just a mixture light that excites both our medium and long wave cones.
So just like our eye's the C6 does not need an additional sensor, only the correct spectral table just like any other display.
There's one thing that's always bothered me about the name of that table...
I believe there is also a choice called LCD Direct View (RGB LED), in which RGB refers to the color of the LEDs in the backlight whereas the Sharp Quattron table is called LCD Direct View (RGBY LED), in which RGBY is referring to the colors of the sub-pixels in the LCD panel itself, not the backlight which is White LED as far as I know.
Perhaps something like RGBY-LCD Direct View (White LED) or LCD Direct View (Sharp Quattron White LED) would be more consistent with the naming scheme the other LCD tables use?