Whether one mixes greens from blues and yellows or uses greens from the tube, greens need to be warmed. Mixing greens for Eastern spring is fun. But I just figured out, not so much a formula but a Guiding Principal. I am a bit embarrassed it has taken me this long to articulate it. To determine which warm color to use to warm a green consider the color of the blossom of the plant. This is crystal clear in irises. The green beneath the very pale yellow under the blossom is a purplish color the hue of which looks to have dripped down from the blossom. I have 5 different irises in my garden and each of them a different variation of purple. Each color is part of the green make especially under the blossom.
While I am sure this is not Gospel truth that there will be times to change the warming hue, but it can be a start to create subtle shifts of spring greens.
Into The Sun