Detail of a painting from 2010There, a eucalyptus tree. Well, the way I like to paint them right now anyway which is not to say you can't paint them any other way. I'm still evolving with my trees with each painting too. This demo I took from a painting done in 2010, and sold to a good friend here in the valley, shows basically a 3 step process I use quite often for trees.
Step One....the basic tree shape is blocked in with the dark shadowed colors. I like to use a mix of ultramarine blue, alizarin crimson and just a slight bit of cad yellow light or pale. for this reddish dark color it would be like UB 40%, AC 55% and CY 5%. I always throw in a bit of cad yellow. The more cad yellow you add the greener it becomes. Try to paint the darks of the tree as thin as possible so the paint can tack up some. If you are working alla prima then try and paint just the areas where the darks will be seen and leave other areas for the lighter colors.
Step Two....you can do this 2 ways. Add a lot more cad yellow to make a lighter mid value green out of your dark mix or just mix up a new batch of mid value greens. I do it both ways. If I am adding to my dark mix I try and save some of the dark mix for later touch ups if needed. Work from the top down and let the dark colors blend into the mid value mix. This fades the light colors into the lower areas of the tree and the shadowed side of the tree.
Step Three....either add more cad yellow to your mix or mix up a brighter yellow/green for your highlights. This is added just where the sun is really hitting the tree. I like to add some yellow ochre too in spots. Yellow ochre gives you that great olive drab color which is perfect for oaks and eucalytpus trees.
There are many ways to paint trees. There are many color palettes and paint combinations you can use. A popular one to use is blue or even dark green shadows....cool colors. I've done those too if I'm not using a warm color like my dark red here. They say there are no rules in art right so you could use any color you wanted as long as it is dark....I tend to use the reds, blues and greens depending on my overall palette of the painting. My foreground grasses in this painting were warm ochres so I went with warm shadows. Had the grasses been spring or winter greens I'd go with cooler shadows like green or blues. This is in keeping with the color harmony working in a painting. Whatever dark you use make sure your other colors have just a hint of it in them to work the color harmony. Dark grey shadows...mix grey greens for mid values and lighters greys to your highlights....it's possible, anything is possible when you paint.