I use this painting to practice the variation of subtle gray colors. The vase and the mug are slightly different in color. I used ultramarine blue, cad orange and white as my core gray and shifted that gray into yellow, blue, and purple by mixing with corresponding colors. I feel satisfied with this one. The value maybe a little dark, but in general I see progress.
In my yesterday's post I mentioned the failure I had. I didn't mean the painting wasn't working, but it was my theory. I thought I could use terre verte and ultramarine violet to mix a purplish gray, but it was not a good choice. The color could not get dark value. Having wrong theories is very common in research. That is why experiments are so important.