M57

Bill,
good luck on the clear sky, it totally clouded over here a few hours ago, looks like the summers over for a while again.

As for the yellow and blue internals on M57, I've seen both.
Compare the folowing links,,
www.astrocruise.com/m57.htm
www.seds.org/messier/m/m057.html
www.umanitoba.ca/faculties/science/astro.../cbrown/imaging/m57/

maybe its due to differing colour responses between cameras.

Yes, it's very variable, and I suppose due in the main to particular equipment. you have to wonder which colour is actually correct. It would make interesting discussion.
Unfortunately the clouds moved in here and are here to stay by the look of it
Bill.