Maile did it in 6 minutes

In the glass she was using for water she made a dark neutral black color by cleaning her brush out.

Maile had 10 minutes before she had to leave to get her plane back to Ohau. First Maile learned that the concentrated yellow pigment looks like the color brown. We took a white sheet of paper and made splotches of transparent yellow, magenta and cyan. Maile was quick to learn the names of the colors and the importance of having her primary colors transparent. Computer Coloring Book

On the yellow splotch she added some cyan to make green. Washed and squeezed her brush out, picked up some magenta and added that to the yellow to make red. That only left the toughest color to make, ultramarine blue. A little magenta on the cyan and we had it. That took care of making blue, red and green, we had the primaries and secondary colors. From there it was fair weather sailing.