Yes, it was tedious the first time I did it, and it took me one or two charts to really understand what a useful tool it is. Richard says it best:
Surprisingly, the charts took only two weeks to complete, and when I finished I knew more about my paint than I had ever thought possible. It was an astonishing experience -- imagine being taken into the kitchen of a great chef and shown everything he could do with flavors -- that was what it was like for me! There was nothing tedious or boring about doing the charts; each was a revelation of the power that awaited me when I did start painting.
I also liked his list of things you learn about colors beyond just how they mix. For example, adding white changes mixtures to a new, cooler color, instead of just lightening the mixture. And have you ever noticed that most colors appear more vivid in the mid-value range?
So after reading this again, I decided to make more charts, just for greens, using the paints I wanted to carry in my pochade box. It was definitely enlightening, even using only three values instead of five. Here's one (I won't bore you with all of them):
A parting note from Alla Prima on the charts:
My advice -- my plea to you -- is to do the charts for your sake. The charts are not a sure-fire gimmick guaranteed to make you a color wizard, but they are the best way I know of to understand your pigments and enter the study of color on sound footing...impatience will well up, so will exasperation as you make mistakes or struggle with decisions about the right color and value, but I urge you to stick with it. In a way, the charts are intended to be somewhat agonizing so that you will develop the patience and self-control so necessary in painting. It should be like an initiation ritual before what is to come, so you may endure it without giving up. As a dancer learns to tolerate paint and endless falls in order to some day soar with grace, so must you have the stubbornness to mix a color until it is precisely what you require to make your painting sing.