We are asked to make a scale between an orange red and a green blue. The object was to try and maintain consistent tonal alues across the scale by adding a little white. At the midpoint, the result should be a grey.
We are asked to make a graded scale between orange and violet, green to orange or violet to green – again mixing in white to maintain equal tones. I’m not sure that I got this right but here goes (all were Cobra wm oils on a grey wash done with oils):


Top line is Pyrrole Red to Ultramarine. I don’t know what happened here because I ended up with a green (not expected) and a brownish purple (which was expected). I don’t know if there was some contamination from the brush or water. Not pleased with the first attempt at all – I think I was trying to get to the colours provided in the image of the exercise.

Middle line – Orange to Red-Violet (my own mix) – middle colours were peach, which I expected.
Bottom line – Permanent Green Deep to Permanent Red Violet Light – middle colours were light purple/violet.

Then I tried Permanent Yellow Light to Deep Violet (made from green, violet and ultramarine). Middle colours were interesting variations of brown.
I found this exercise a bit of a challenge and will probably go back and do some of these tests again when I have pure pigment in tubes to work from.