Subject: If the sun were red, what colour would the sky be?

I am interested in how the output of stars of various spectra would affect 
the colour of the sky (in particular, but also object on the ground)
assuming one is standing on the surface of an Earthlike planet (unlikely 
for some types of star, I know, but...!) It`s the sky colour that is the 
biggest problem for me, might be able to work out surface objects colour 
myself. A way general way of working out sky colour from spectra + 
atmosphere mix would be nice, but  I`m not expecting miracles! I am a 
middle-aged SF fan capable of degree-level physics unable to pursue degree 
due to circumstances. Assume slightly better than new 1st year degree 
student ability.  Oh, this is personal interest question. Many thanks! Esme

Re: If the sun were red, what colour would the sky be?