I recently picked up some Gamescience dice (through Gamestation.net) and they are beautiful. These are the hard/sharp-edged dice from days past, and, yes, you still have to paint in the numbers yourself (though you can pay a few dollars extra for prepainted die.)
But if you want some classic dice and would like to paint in the numbers, here's an easy way to do it:
1. Gamescience dice are molded on a sprue, just like plastic model kits, so they will have a bur on on the edge of one face. You can get rid of this bur by either carefully cutting it with a sharp blade, or by sanding it off with some fine-grade sand paper (as is shown in Step 1.)
2. Get some paint (whatever color you like!) and cover the engraved number with the paint. Be sure to get the whole number filled in.
3. And while the paint is still wet, use your finger to rub off all the excess.
4. You may have seom streaks left over. These can be rubbed off with your finger, or gently scraped off with your finger nail.
5. That's it! Beautiful dice. And I like the idea, now, that I have to prepare my dice. If I've dedicated some of my time to the dice, perhaps the dice gods will give me a few more 20s.
Note: This particular color is not "available," per se. I chose Gamescienc's Fire Garnet, but the color was out of stock. When the new dice were molded to fill my order, I got an e-mail that an off-color had come out instead. I was offered the off-color or to wait for some proper fire garnet-colored dice. I kept the off-color because I wanted something fairly unique. I'm glad I stuck with this new color. They are gorgeous! The best I can describe the color is that of a deep rose wine.
And I know I probably won't be able to get any more, sigh.