The bright colors of autumn foliage are really fun to paint, but there are some things artists have to watch out for when creating these seasonal landscapes.
For one thing it's very easy to for fall scenes to become unnaturally bright and over-saturated, this has to do with color relativity and the way we perceive color. Color relativity is a complex subject (you can read about in more detail in these two posts: Color Relativity Part 1 and Part 2) but in a nutshell- each color is influenced by the colors surrounding it. Autumn landscapes tend to contain a lot of complementary color pairings; when these colors are together they often intensify each other, and as a result, the foliage (and sometimes even the sky) can be perceived as being brighter than it really is.
Color Temperature- is another area that can be difficult to control in the autumn landscape. (If you'd like to learn more about color temperature I have a post about it here.) It's easy to make the overall palette too warm when painting fall scenes (after all, reds, oranges, and yellows are generally all on the warm side of the color wheel). There are cool colors in the landscape, but they're easy to overlook in the midst of all those warm, bright, eye-catching, hues.
To combat these common pitfalls here are three things to do when painting a fall landscape:
Lower the saturation: Pick colors that are less intense than you think they should be. I always recommend to my students that they avoid colors like caution yellow, construction orange, and fire engine red, when painting a fall landscape. Instead, opt for versions of red, orange, and yellow that have a touch of brown in them. These toned-down colors are more natural and will fit into the landscape better.
Remember, it's easy to pick over-saturated hues because there can be a lot of complementary color pairings in the fall landscape (e.g. blue sky against orange foliage; purple influences in soil, foliage, or tree bark, set off by yellow foliage or grasses; green foliage, or grass mixing with red leaves). These complementary color pairings tend to intensify each other, which makes us perceive these colors as brighter, and more intense than they'd seem if they were on their own.
The good news is color relativity works both ways- so when you opt for subtler less-saturated colors and place them near their compliments, the colors will seem bolder, brighter, and more saturated, than they would on their own. So by opting for more subdued colors you won't be missing the pop of color fall is known for, you just won't end up with a palette that feels unnatural.
Look for the cool colors in the landscape: Often when we're looking at foliage it's the contrast between cool and warm, rather than how bright a color is, that makes it stand out. As I mentioned above, the fall palette can be quite warm- so to create a balanced piece, you need cool colors to counteract all that warmth. When you're painting, make sure to look for the cool colors (or the cool versions of colors we normally think of as being warm- like red) and include them in your piece.
Typically there are cool versions of red and orange in the foliage, even cool versions of browns too. There can be purple overtones on the ground or in the trees. Other places where it can be interesting to add some cool notes are in skies or water.
Don't forget the neutrals! Neutrals really are the backbone of landscape painting. If you build a scene using colors that are more neutral first, you won't need more than a sprinkling of bolder color to create drama. This approach also makes it easier to not to overdo the bolder more exciting colors.
I hope these tips help you paint more natural, and harmonious, autumn landscapes.