Oh well, back to the drawing board it is. Thanks, Fleeting Frames, for the input.

1. Light colors, especially cyan are always a problem, but I don't think there's much I can do about it. Maybe I'll fine-tune the colors some more and add a little bit more embossing to the letters to increase the contrast.

2. Oops, forgot about that one since my screen was is a bit too dark, which made the difference almost invisible. I guess, default black background will come back. I don't want to change all the black pixels in the tiles to this almost-black and screw everybody who doesn't like my color choice in the process.

3. Half-transparent pixels at the edges are a pain the posterior for those tiles that ignore transparency. The extra wide walls will stay, but I'll shave off the edges, so that the difference between the corners is a bit more than just one pixel.

4. I do not recommend showing the engravings by default with this set. In fact, I'd never recommend it, but that's a matter of taste. I made these floor tiles so that engraved floors look awesome without it. Especially the tiles that are extremely annoying in default ASCII like schist, orthoclase and microcline are rather nice now.

I'll post an update soon, so stay tuned. And I guess, I'll drop photobucket, since it seems to mess with the pngs in some way.