You need to think about lighting and where is the light source? Light and where is the light coming from? Outside light is pretty much all around, but there will be a stronger light source; the sun. That’s number one. Number two: what season are you painting; what land where is the sun in the sky? The angle of the sun changes where the highlights will be on landscape. Clouds effect shadow and shade on trees etc. Very important…….how does Distance change realism! Trees in the distance is NOT in focus or realism as trees that would be twenty feet in front of you. Stand outside and LOOK at the landscape; sketch, or doodle what you see, even take a few notes.
If it is a painting of a night subject there is a light source as well.
If you were to take five leaves off this Hydrangea tree and lay them next to each other on the table the leaves would be the same color. True? Notice how the color changes with the position-depth of the leaf in the center of the bush/tree. The color changes because of the way the light hits that particular leaf-leaves. Leaves with more sun light have a warmer color and tone, more yellow color to the base color. The inside leaves are cooler in tone and not in focused as the fore ground leaves.
In landscape you need to be aware of distance and how that distance changes realism; up close landscape will be in focus and well rendered verses landscape in distance. The trees for example become design in colors. Go outside and NOTICE what and how distance changes realism.
Painting outside is the best. but if you can not paint outside at least take several pictures for your reference. Use warm and cool tones in your benefit; Any cool toned color will sink in space and a warm toned color will come towards you.
realism vs. the trees in the distance.
In all the above pictures notice how the color changes in distance trees and the design as well. In the direct above picture notice how these are two of the same tree about 100 feet apart. The realism of the tree in the fore ground is more realistic, so you need to draw it that way.
THINK of landscape as an Ariel perspective and picture in your mind the distance in panes or recessing values as the drawing value scale. Number ten on the value scale would be in focus and or the surrounding will be in sharp rendered realism [where the viewer is standing]. The next pane or slice [away going away from the viewer] will be a slight bit less in focus or realism. The third slice will be less in focus or rendered compared to the second pane and so on. When you paint the far distance such as mountains in the distance they are NOT rendered and are light in color and values.
Learning to see the details around you; what a leaf or tree for example looks like when you are standing next to it versus how a tree or the detail of a leaf look in comparison farther away or distance. Take the time to look and notice color and how the color changes and the details or realistic details slightly become unfocused as they go back or a way from you in distance.
I advise you to start thinking about color or graphite in values [one to ten; light to darkest] for all colors as well as grays/blacks. Are they warm or cool in tone? Warm tones will come forward in space and cools will sink in space. The way God designed it, not an artist trick. Think about how color fades in distance and lack of detail in landscape.
Don’t worry so much about the name of the color printed on the tube of color, look to see if it is warm or cool in tone and where would you use it on form, shape etc.