I used gouache colours for this mixing, as I found the translucency very attractive. The tones that develop from hints of white, grey and black are interesting as they turn dull or brighten shades. Mixing touches of the primary colours too. I spent a while with this, and have several other sheets which are not uploaded.  Interest that red is not so vibrant as I anticipated, and certain colours that I find attractive have into come into this range, eg fuscia pink, my own perception of lavender blue. Once again I see I am just scratching the surface of a massive concept.