Chroma — Reveal the top ten cards of your library. For each blue mana symbol in the mana costs of the revealed cards, target opponent puts the top card of their library into their graveyard. Then put the cards you revealed this way on the bottom of your library in any order.
8/1/2008 Chroma abilities check only mana costs, which are found in a card’s upper right corner. They don’t count mana symbols that appear in a card’s text box.
8/1/2008 Chroma abilities count hybrid mana symbols of the appropriate color. For example, a card with mana cost has two red mana symbols in its mana cost.
8/1/2008 If there are fewer than ten cards in your library, reveal them all. For each blue mana symbol in those cards’ mana costs, the targeted opponent puts the top card of their library into their graveyard. Then you reorder your entire library as you choose.