I'll admit that the inspiration for this color scheme and feel came from a trip to the grocery store. I saw a basket of plums and besides making me salivate I was drawn to that deep purple color.
So often when we think of autumn colors it is orange, gold and red that first comes to mind, but if you look closer you'll see deep purples and yellows along with those fiery reds.
I searched pinterest for plum and yellow interior design and found some beautiful spaces.
When I teach Interior Design 101 one of the first places I recommend people look for inspiration is in nature.
So go take a walk and see what nature inspires and maybe bring some of those colors in to liven up the house for fall.