Step 1 - Using white and true blue I lightly shaded the light and dark values. I used the side of the sharpened pencil and mostly used a circular stroke, sometimes used a back and forth stroke, to smooth the pencil marks.
This is another photo of step 1. Note the differences the lighting and camera can make.
This is step 2. I went over the green areas with canary yellow and the red areas with crimson red, lightly, using similar strokes as before. I did put a little crimson red into some of the darker green areas.
Here I added peacock blue, then spanish orange to warm the green and red. I then used indigo blue for the dark areas and some grass green. I also started adding more crimson red layers. This is now in the middle stage in some of the sections. This is a demo piece so not all areas are at the same level. More layers and blending to come in the next class. Work lightly and build the layers.