If you can get your hands on them, the Encyclopedia Magica volume 2, pages 785-795. The entry has the original source as being the Dragonlance MC Appendix. It includes the history of where the orbs are from and what each color orb does as far as powers and such go. I hope that this information will be of some use to you...
i am tentatively trying my hand at writing a campaign featuring the mighty dragon orbs. i am hoping to come up with some original concepts and ideas, and steer clear of too much dragonlance cliche. the places i am hoping to run my campaign, i have little information on. if someone could direct me to some source information for the following cities, it would be greatly appreciated (was any stuff ever published in any of the 2nd edition stuff?);
niole dra
gradsul
loftwick or any well detailed yeoman city/town. also, what sources exist regarding the orbs of dragonkind? i think i remember reading that they were likely constructed by imperial suel, with their fetish for binding, but at some other time weilded by the oeridians. is there any good sources for this kind of thing? feel free to reply with suggestions and experiences if you have ever tried this plot. thanks
My suggestions for the cities you mention as far as resources are the following: Living Greyhawk Gazetteer (available for order from Paizo), the 2nd panel of the WoG map in Dungeon #119, the Against the Giants series of modules, and try following some links from the RPGA site to Keoland and the Yeomanry for more "unofficial" information. I'm sure there's a ton more out there, but that's all I can think of for now.