Many books have been written on colour in calligraphy, for calligraphy: Sheila Waters, Marie Angel to name two.
Then there is the gouache/water-colour debate as well as the MAKE of paint debate....and on it goes.
Well before I started calligraphy my father bought me a Winsor and Newton ater-colour paint set which I still use today. Together with sable brushes a friend gave me from her mother's paint box I am well set when I go away and love to create colours using the scenery and objects around me.
I have a colour 'bible' with notes compiled from hearing many people talk 'colour, colour, colour' and then creating my own colour wheels, lines and swatches. The most impartant thought I keep is that although there are 'warm primaries and coll primaries' you have the whole pallette to work with and can use arbitary colours such as Payne's grey for blue, terracotta for red and ochre for yellow for another wonderful theme. Don't forget to add complimentaries to primaries for shadows and whites for tones....the opportunities are endless.
Why not find your paints and some paints and create your very own colour wheels....you will be amazed!