The Game Boy Color will be released in Japan on October 21, but if you live in North America, you'll have to wait until the November 23 release date here. Recently, Nintendo released screenshots of its first few color titles to the Japanese press, and now we have gotten our hands on clearer versions of these screens.
From the title screen, it looks like Zelda will be released separately as a Game Boy Color title, as the title screen indicates a 1998 copyright. Metroid II and Game Boy Gallery seem to be the standard cartridges with a preprogrammed palette inside the system, but that has not been confirmed.
Tetris DX (Deluxe) and Wario Land II are new games in Japan that are specifically tailored to the Game Boy Color and are launch titles for the machine. It's not known whether the US Wario Land II (released last spring) will be in color on the older version or whether there will be a new version.