There is a matching alcove to the left of the fireplace.

In my opinion, the scale of your bookshelf is too small for your 12 foot ceilings (lucky you!) . Likewise, the items on the shelves are too small for that scale. You can try removing all the items and try a huge object on the top shelf (vase, basket, etc...) also remove the top glass shelf and add a few large objects to the remaining two shelves. With ceilings that high, you need to think BIG. I would also replace the light bulbs in the niche with recessed lights but if this is not possible or not in the budget, two ceiling mounted spots would be preferable to the bare bulbs. I feel the shelves can be restaged successfully but if you are still not happy with them, you may have to have new ones built. Need more photos of the room to comment on colour.

I would take it out and start over. Larger and to the ceiling

Leigh, Thanks for your thoughtful reply. We moved into the house 3 weeks ago, had 2 arches removed from the alcoves ( too many arches elsewhere ) and that is why the bulbs are showing. Ugh! They of course will go.
I did some rearranging on the shelves but want a more finished focal point including the fireplace and shelving...I think going to the ceiling is too high...
Hope this photo will help re color.
TY

Just realized the photo doesn't show the valences at the top of the shelves, they would hide your bulbs... will see what I can do.

I'd do "floating" glass shelves from top to bottom matching on both sides of the fireplace. Then, do two recessed canned lights above in each alcove. Here's one with cabinets below. You could do that on both sides as well.

showing valence

I'' partial to the Guilford Residence pic above as the decor is the least cluttered, it is lighted well and is a soft contrast with the trim paint. If you use glass shelves, your lights could be replaced with some LED cans and might illuminate the area nicely. Def take it all the way up.

Both the pictures are so helpful. I am now converted to the idea of white shelves...still have an issue about going to the ceiling as one of the alcoves has a built in speaker above it. Any suggestions as to the what dimensions the valence/cornice header should be... (don't want it too skinny or too heavy looking)? TY again!