David,

Do you use AWB or set it manually?
I sometimes (not always) get a cyan cast to a blue sky which is a bit of a pain.
You will appreciate that when in the lovely clear air up north (north of Aberdeen that is) it should be a clear blue.
Other cameras seem to render the colour better.
Probably a mix of SAL 18-250 and SAL 16-80.

Any comments welcomed.

Mike

I have the same issue. Using AWB while shooting BIF I mostly get an aquamarine kind of blue. Also, in darker conditions, AWB will tend to make the WB very cool.

If you are shooting raw Mike, then using a camera profile such as Deep (if you can find and install the profiles) changes the sky colour from Ektachrome 50 (cyan) to Kodachrome 64 (purple) blue.

David