MTGNexus

If I Craft Sunbird Standard with a single card, say Invasion of Alara will I be able to tap Sunbird Effigy for wburg?

I've got the feeling this is too good to be true and its somehow only identifies with one color per card ..

Actually yes, if you craft with a single WUBRG card you can tap for WUBRG because all five colors are "among" the colors of the exiled card. (The creature will also be a 5/5.)