Are they any good?
How would they compare to top-tier universals such as the Westone 4's and SM3's?
What is the difference between faceplate and shell color?
I have not personally used them.
They would theoretically have increased performance vs. any universal because of the individual tuning to one's own ear canals.
Faceplate color is the color of the plate that is visible when the monitors are inserted in your ears, and the shell color is the color of the body of the earpiece.