Even if you knew the brand and exact paint, touching up a ceiling after this much time has passed never works out. It always shows. Even touching up a ceiling a week after painting it is difficult because usually kitchen ceilings are soaked in natural light from windows...all that light coming in really makes touching up difficult. You probably will need to paint the whole thing.

Paint them both

Put a strip of molding across the intersection?

After 12 years, the ceiling probably needs to be repainted.

Thanks guys: Kinda figured that (will paint both ceilings)
thanks much
Bill

Probably more than you want to do, but our kitchen is open to our family room, but we put a soffit in to make the spaces feel separate, even though they are one. Makes different ceiling treatments easier.