Type carries the restrictions.
I´m afraid that is not entirely accurate.
Workshop mana drained with Drain Power is colourless mana that you can use to play whatever you´d like.
The relevant entry of the comprehensive rules, under the glossary text for "Mana":
The “type” of mana is its color, or lack thereof (for colorless mana).See also the FAQ of Doubling Cube, this was the first time I saw this relatively new rule.
I assume that with Piracy you add the mana directly into your pool, which means that the Workshop restriction still exists.