Can the color of a round fancy color diamond be improved by cutting it to Ideal proportions? Most cutters and gemologists say no, because cutting a fancy color diamond to an Ideal increases brightness, thereby diluting body color. But others say that, in some cases, fancy color diamonds can be cut to Ideal and not only keep their color but also improve their performance. “Mr. Swiss,” a European businessman who owns an important collection of fancy color diamonds (and who wishes to remain anonymous), recently had a Fancy Vivid Yellow round brilliant recut into an Eightstar Ideal. He believed it was too saturated to lose much color. He was right: The stone is still a Fancy Vivid Yellow diamond, but with far better brilliance and dispersion. Stephen Hofer, renowned colored diamond expert, says this is the result of what he calls “on-axis reflection”—internal reflections that