One more vote to explore raising the ceiling instead of lowering the floor. In addition to lowering your home's value and making it a "definite no" to a lot of future buyers, you would make your house more dangerous to young children, older visitors and completely off-limits to anyone with accessibility issues. I live with brain injury I sustained at age 32 caused by tripping. It didn't seem like a big deal at the time, but it ended my career, as well as any potential to do anything else. It wouldn't take much for a guest to trip and crack their head. Would you be able to live with that if they sustained the damage I did? Could you afford the lawsuit that might be leveled against you? The increase in your homeowner's insurance if they knew you had that danger in your house? PLEASE don't do this. I apologize for the strong response. I just can't stand the thought of someone living with the headaches, vertigo, nausea, blurry vision, memory loss, etc. etc. I face every day. Especially if it can so easily be avoided.

May want to decide if you want boldness or softness - see below. It looks like the counters are on the softer side so would start there before choosing the other accent color. If you search Pinterest for “blue and orange (or tangerine or yellow) paint“ you’ll see the combinations that feel bold or soft and are complementary. Many include the paint names. Have to allow that lighting in room will affect their results, but at least they will have the same vibrancy.

Cute pooch. Is the eighteen feet from the by window to the tv? If so, you could leave six feet between the back of the sofa (centered with the bay window) and the bay window for your play area. Then use the rest of the area for your living room space. If you want to try centering the back of the sofa across from the bay window, then measure the space between the side of the sofa and the wall with the two smaller windows. It may be that you have room there to place your desk/table with metal legs in that spot with its chair sitting in the play area. A tall thin metal lamp with large white shade on it could serve the living room as well as the desk. If not, find another side table/cabinet for that space for that purpose. You could plan a place in the play room for a bed for the family pet. Underneath the bay window, you might want a window seat that doubles as toy storage, preferably with front doors if the children are small. A top lid can pinch little fingers. https://angelarosehome.com/ikea-besta-bench-hack-with-diy-cushion/ Unless you're wanting a wall to wall built in underneath the bay window -- if you're wanting separate pieces of furniture, then on each side of the window seat, you might consider tall shallow cabinets with solid doors at the bottom for some hidden storage) and either open shelves or glass doors above for displaying family photographs and family treasures.

You should get one of those "star projectors," https://www.amazon.com/Planetarium-Projector-7-Constellation-Adjustable-Ambiance-QBrand/dp/B09QLT179C/ref=sr_1_51?crid=3CUBK23TMNVQS&keywords=star+projector&qid=1657476969&s=home-garden&sprefix=star+pro%2Cgarden%2C88&sr=1-51 They're fun, great for creating atmosphere, plus its an easy addition to the room, not a permanent change and when the kids no longer need a play room it can easily removed, so the room can become a more adult space.