Extremely subtle color differences can be very important to determine rarity of a diamonds, but are never a critical factor in beauty.
Flawless ideal cut diamonds are no more beautiful to the unaided human eye than a grade in the middle of the scale. Once again, extremely subtle differences in clarity are very important to determine rarity, but only affect beauty when in the very low end of the scale.
Uncut loose diamond look just like gravel or pebbles. It`s only after the professional diamond stud cutter has cut the diamond stud that theirs real beauty is revealed.