This book has an academic quality, not surprising since Feisner developed the colour courses taught in the Fine Arts Dept of Montclair University in New Jersey, USA. The chapters include: What is Colour? / Various Colour Wheels / over a dozen Colour Theories through several hundred years / Colouring Agents like pigments, dyes, binders / Dimensions of Colour such as hue, value, intensity, temperature / Using Colour in principles of design and in elements of design space / Colour Interactions / Colour in luminosity, iridescence and luster / Colour Symbolism / Putting Colour to Use (past and present).
Probably the most thorough book on colour I have come across.
I also like Hart's "The Watercolor Artist's Guide to Exceptional Color" and Edwards' "Color". There's also Wilcox' School of Colour website where he offers his 400page "The Wilcox Guide To the Finest Watercolours", a truly comprehensive guide to watercolour paints. The book lists and describes the lightfastness and pigments in all leading manufacturers' paints. An eye-opening guide.
I plan to get his set of 12 watercolour paints described as "Although a huge range of colours (most pre-mixed), are available on the market, it is difficult to find any outside of these twelve which have a serious application in colour mixing." To my surprise, his set of 16ml tubes are cheaper online from his website than buying them individually in the much smaller half-pans from art shops.
His palette is very clever: I saw a new student achieve much better colours than most of the advanced students in my mixed class (that's how I learned about Wilcox).