I attended an oil workshop this year and when any student in the class asked how to mix a particular color, the instructor would always say...red, yellow, and blue. And she was right! Of course, white is also needed, but that's what this piece is all about. The very dark brown in the background is the color orange with a less yellow and a lot more red and blue. The light foreground color that is the color of hay is a small bit of "grayed down" orange with lots of white. And of course, the pumpkin is what we would normally identify as orange.
When looking up the word abstract...some of the other words that describe it are words like abbreviate and summary. I like those words because they perfectly describe what happens when an image is abstracted. In this case, I am giving the viewer an abbreviated image or a summary with many details left out. For instance, the orange in this piece is definitely a pumpkin, but the "ribbing" and minute shadings in the pumpkin are absent. The stem helps to differentiate it from an orange, but even there, the details are left out.
The foreground color represents hay by its color and value changes, but every straw in the hay bale is absent. This is an exciting approach and hope you will try it sometime. The palette knife is the perfect tool for this because it creates the erratic edges that happen, especially when painting "wet into wet". This piece was done in acrylics with retarder added to the paint. I love oils, but it is very difficult to include lettering in oils. I also have plans to make an extended return to "Open Acrylics" which stay wet for a long time, but will also enable me to write on it with water soluble media. And there you have it...just a few more things to think about.