There should be no difference at all between Full and Limited whatsoever. They should look 100% identical. Try to play Last of Us with Full Incorrectly set and enjoy not being able to see any shadow detail whatsoever.
Again, the colors are not deeper, richer. What you're failing to understand is that calibration is a standard - it's not subjective - it's entirely objective. There is only one standard to calibrate a TV to. Going and just fiddling with your settings isn't calibration at all. Calibration is done by a professional that has thousands in equipment.