Another thought- a kitchen table - rectangular - could double as dining seating and added preparation area. The above proposed floor plan seems to devote a lot of space to a dining area, at the expense of a living area with space for art studio.

I would lean into the color drench, but in a softer mid-tone green rather than the deepest shade, so the small space still feels cozy instead of closed in. Keeping the trim the same color will help the low ceiling feel less choppy, and warm layered lighting will matter even more with only one small window. Since your paintings will be the focal point, a muted green should let them stand out beautifully for Thanksgiving.