Mine was against the garage but not where the foundation is exposed to the elements. Put a long level against the wall and set it plumb. Carefully check along the width for the gap against the concrete to see what thickness you must fill. On ours, I ended up chiseling away several concrete knubs left by the forms, cutting and anchoring some plywood (1/4" as I recall), and gluing drywall to the plywood. I'm sure I had to shim the plywood in places too. Can't recall if I then used 1/2" or 5/8" drywall but the finished result blends perfectly. Another option would be to set drywall proud against the concrete and cap with a nice piece of wood. Hope this helps.

Don't buy anything until you try the simple route first. Remove the stairwell gallery and the stuff on top of your kitchen cabs. Try clearing the countertops a bit. How many pets do you feed? Can they eat together and stay friends? Organize one pet feeding/watering station outside the living area if possible. I see three huge bowls in the floor and they are a trip hazard as well as being unsightly if your furry friends don't eat every bite. Address the clutter in your TV center as well. Try 1/3 books, 1/3 larger decor items and 1/3 open space in the shelves.

I do think somebody went a bit overboard with the two-tone effect on that one. I'd probably consider painting it all white, except for the base and cap. Although, if there are other elements of the rest of the house and your styling that work with the idea, there is always the concept of a contrasting painted post:

In the photos all the colors seem to appear grayer/bluer than I would expect from how the colors normally appear. That does point to a lighting problem. Not enough natural light combined with not enough indoor light, and maybe not the right color temperature of indoor light. If you have LEDs in your ceiling fixtures, it could also be a problem with poor color rendering (LEDs vary a lot in their color rendering index, or CRI--look for 90 or higher). If you have LEDs, I would check the lamp characteristics first. If the color temperature is above 3000, or the CRI is below 90, that could be your problem. I think Herbflavor may be right though: Your current lighting seems in adequate. Your kitchen would probably benefit from more lighting fixtures (recessed cans) and more total lumen output. Warmer color temperatures (2700-3000K) should help bring out the yellow in the Ivory Lace.