GREEN entries are games with "complete" sets -- though they may only have in-game or manual checked, and conformation for the other would be appreciated as credits can differ between the two.
YELLOW entries have either a transcription available elsewhere with no source, a source available for another (usually English) region, an incomplete source, or evidence of credits existing in the game such as text or graphics visible in the data.
RED entries currently have no known credits source, or only credits to individual staff rather than a full listing.
If you have anything you'd like to contribute (such as screenshots, video, or scans of credits), or information on missing items (including confirmation of a game or manual *not* having credits), feel free to contact me via Twitter or my GDRI talk page. Keep in mind that I am specifically interested ONLY in Japanese releases for the purposes of this archive, though of course getting sources for any credits out there is obviously a good thing. :) Any help is greatly appreciated!
Sega Mega Drive / Mega CD / 32X
NEC PC Engine
Nintendo Virtual Boy
Bandai WonderSwan / WonderSwan Color