Color wheel tools

[Elizabeth Schott]

Based on a suggestion is Chris's book, I purchased a color wheel with values, color relationships and tones (doesn't have the analogous reference), A "Quiller Wheel" - that I for the life of me, cannot figure out how it helps with pastels and the Michael Wilcox "Color Mixing Workbook", which is a wonderful rainy day exercise, I also like to document each work by journaling the color here.

But is there anything that is just helpful to the pastel artist? Sometimes the simple statement "grayed down" can take on so many applications because of the nature of pastels.

I would really appreciate a "Pastel" tool suggestion.

Thanks!