Hi kwwd-
I love, love your spool chairs with the blue and white cushions!
I cannot tell what color the walls are. If they are yellow and you plan to keep them that color, I would reinforce that in your accessories such as the throw pillows that go on your chairs. Maybe something like this,
or you might want something with more of the colors in your paintings.
I like the idea of making that space a library, with a shelving system that you can either have built in for $$$$ or that you can do less expensively by doing yourself if you are handy..
What you might want to do is have the shelving system white and paint the backs of the shelves blue.
Or, if you're the kind of gal that likes to retain the prerogative to change her mind, you can paint the shelves white cut a piece of foam core and paint that blue and put it on the back of the shelf, and then when you decide you want to change the color, you can.
(Take a look at the thread of C Renee how she painted the back of her shelves blue. https://www.gardenweb.com/discussions/5131257/need-throw-pillows
Her thread also has some great throw pillows suggestions too.
Your primitive paintings are lovely and you can incorporate them into your bookshelves as well.
Here are some examples. Please note that some also show picture lights and wall mounted lights, something you might want to consider, so you don't have to worry about table lamps that take up a lot of space and limit the positioning of the tables near outlets.
Sliding library ladders are marvelous. Fractured hips from a fall, not so much, so do think about that.
Maybe those two spool chairs could go at a library table, (if one would fit in the room) and you could bring in the club chair from your sunroom that you reupholster in a sturdy white material and you might want to add a comfy upholstered footstool.
If a library table would not fit, your side tables which look like spool tables too (love, love that idiom!) would be perfect, and you might want to think about painting them to match your chairs.
It won't be too much white when you have grounded your room with the colors in your paintings, the back of the bookshelves, added art and collectibles to your bookshelves and a live green plant to the room.
I always think it is a good idea to go to a store that sells upholstery and drapery weight fabric and see what catches your fancy, (take a snapshot of your painting and furniture and wall in good daylight on your phone when you go shopping) and sometimes you can have something made up for less than what you can buy it.
(Besides, to see and feel all those luxurious fabrics in so many patterns and colors and textures just makes me happy, it's a day well spent!)
Q