The days are getting noticeably shorter! Not looking forward to that. Oh well, part of living in the northern hemisphere. Good old 48.7519 degrees N, 122.4787 degrees W (Bellingham, WA)
So you may want to upgrade lighting, get your skylights cleaned (or replaced), and maybe have some fresh, bright paint applied to the inside of your home. There are many variations on white, and a nice contrasting color on one living room wall will just highlight the bright color.
Another thing many homeowners are doing in recent years is opening up the home’s interior by having a wall removed. No more small, dark rooms, as some older homes were built.
Even the flooring selected will affect the brightness of the room. Carpet, wood, or manufactured materials, color will add to the feel of the room.