Sapphire - Blue, will probably always be the most popular sapphire color. Burmese, padparadscha, Kashmir, and Ceylon sapphires are among the most expensive. Royal and cornflower blue are the top colors of blue, as far as pricing. Sapphires can be treated with (glass) or beryllium making them far, far less valuable. Any dyes or treatments other than heat are generally unacceptable in the fine gem trade. Unheated sapphires bring a premium price.