It's all good. Not going to begrudge you something you didn't know. Hell, I only found out how it works recently.
Just for the record. When done properly, png transparency is really quite nice. It's what allowed me to get the smooth outlining in the character sprites; the "solid" outline is actually only 95% opaque, and there are individual pixels of various opacities (50%, 33%, 25%...) placed around rough edges to smooth them out. Not only does it create the illusion of a higher resolution than we're actually using, the partial transparency allows the character to "blend" a little more in various environments, leading to a more realistic look. That effect, actually, is one of the things I want to talk to people about in the artists' meeting on Saturday. It also has some very fun potential applications; if you want, say, a shallow pool of water, you can just make the floor sprites for underneath, then overlay semitransparent water tiles on top, making it more realistic as well as reducing the time needed to get the proper look. Some items, too, such as potions, can be semitransparent, to achieve a far greater "liquid" look (in most games it winds up kind of looking like they're drinking paint...

). Things like that aren't possible with the pink trick, but the real possibilities now available to people haven't really gotten widely enough known as yet.