Extremely subtle color differences can be very important to determine rarity of princess cut diamond, but are never a critical factor in beauty.
Certified engagement rings tend to have fewer of these tiny imperfections than mainstream stones. The less loose diamonds are ‘included’ the better they are able to reflect the light which passes through them, which intensifies ther’s beauty and fire.
Instead of just white, wedding ring actually come in a rainbow of colors because loose diamonds can be as colorful as any other gem.