Pyroblast can target any spell or permanent, not just a blue one. It checks the color of the target only on resolution.
04-10-2004
wotc
The decision to counter a spell or destroy a permanent is a decision made on announcement before the target is selected. If the spell is redirected, this mode can't be changed, so only targets of the selected type are valid.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.