The main idea behind “Interaction of Color” is that the original was a large book that included (dozens of?) large colorful cards, and the focus of the book is on exercises in playing with colored paper and seeing the relationships created thereby.
The actual “theory” of the book is fairly basic, but I think the approach (i.e. learning by repeatedly doing) is definitely the right one. If you buy any recent printing, you have to force yourself to make your own and do the exercises, if you want to get the full value from the book. Comparing with other students working exercises at the same time would also probably be helpful, even if there are only two or three of you.
