We tackled the wall of green again in my classes at my studio this week. The source photos I used for my demos conveyed several vague varieties of green, including the elusive "grey green"...another tricky color to handle.
When the true color just doesn't translate accurately from the camera, I think it's up to the artist rely on his or her own knowledge of values, color temperature, and color intensity. In some cases, you can slightly exaggerate what happens with atmosphere and distance--through small shifts in color temperature, hue or value--and enhance your artistic message in the painting.
|Shady Spot, oil, 8x10|
When working with a very green landscape, I tend to work in other various colors to balance the greens, often pushing the green hue into a different color family that will still convey the same temperature or vibrancy.
With the large amounts of similar looking foliage, I find it helpful to start by carefully organizing the composition into a few distinct shapes. Below are my initial block-ins for each of the above demos, along with the reference photos used for each: