Q: color slides after sunset

[ABreull@aol.com]

Hi, All:

When you take color slides after sunset, specially on cloudy days, usually
everything becomes blue, although the eye percepts different, e.g. dark grey
instead of blue clouds. 

Has anyone experiences on how many f stops the lens needs to be opened
(compared to the lightmeter measurement), to get colors which agree to the
human perception "approximately" - or do you need to estimate color
temperature in any case and use color correction filters ?

Any advice appreciated ... 
Alf