Hang on a second. You have a desk on the other side of that bar, which likely means neither side of that peninsula is counter height. You can keep the end pieces, but you may find you need new boxes to create a functional, counter height peninsula.

I would go with a white glossy subway tile.

Judging from your picture of the peninsula, I think you'll need a few adjustment to the base to make it counter height. It could look something similar to this.

A new ceiling semi flush light to replace the light box and roman shades on the windows.

We were planning to put soft cream counter with soft cream 3 x 12subway tile lined horizontally. Or brick design? Since we couldn’t raise the desk side we are building a new one counter height, I think. I was wondering if we should use the oak backing off of the old and put on the new? How would that look? Painting the new front facing the kitchen dove white?? Four drawers, two smaller on top, two larger below. Trying to coordinate peninsula, flooring, and oak with countertops. I don’t want the peninsula to look new. I want to blend in with existing.

If you install a $10 temporary light fixture (bulb and socket) where you removed the old ceiling fixture, it'll be a lot easier to see what needs doing. Such as this: https://www.acehardware.com/departments/lighting-and-electrical/replacement-parts-and-accessories/sockets-and-holders/30848

Here's an idea with a light countertop with matching backsplash: