One of the popular and common options amongst the colored diamonds is the yellow diamond. No wonder, most people love to flaunt beautiful yellow diamond engagement rings on their special days.     The color of a white diamond is usually graded from D to Z; the stone that is closer to D grade is colorless and it will start showing color tints as it goes higher on the grade scale. A stone closer to Z grade will show some yellow color tints. Such diamonds will be less expensive when compared to their colorless counterparts. Yellow-colored diamonds are different from that – they will be more expensive when the color tones are higher in the stone. Canary diamonds are the most expensive yellow diamonds out there, which boast a rare and intense yellow color. The main reason for this yellow color in diamonds is irradiation. However, you can also see some secondary hues in yellow diamonds such as green, orange, brown, etc., due to the presence of other impurities.