Mentally divide the scene, which you are interested in painting, into three areas.

Assign one area to each of the primary colors.. red, blue and yellow. ( Actual colors may be whatever...for example....one combination could be green vegetation( Y) grey sky (B) and dead leaves( R)

Ask yourself how the three areas relate to each other in value?

( Which is the lightest,and which is the darkest of your three areas etc)

Ask your self how they relate to each other in Chroma ?

(which is the least chromatic and which the most chromatic?)

Finally just look at the scene as a whole, for the general effect, and take a mental "snapshot"

Go home and, in indoor light, try and reproduce the effect in a very small sketch ( 3 or 4" max on a side), making sure that all of the relationships observed outside on location hold true for the sketch inside.

Comment....I found that I could only do this by looking away and concentrating on asking my brain to assess the whole scene as a unit....trying to train myself never to resort to looking from one part to another to make comparisons. 

* Reference..The Training of the Memory in Art and the Education of the Artist, Horace Lecoq de Boisbaudran Published 1847