I had a mosaic glass tile sheet from Home Depot that I trimmed to fit perfectly in the middle section of the door.
*A helpful hint* mosaic tile is so easy to customize the shape you need because, most of the time, all you have to do is score the mesh sheet on the back with a knife, no messy wet tile cutting!
I didn't want to do the whole grout thing with this because I don't like to grout and I wanted something more water resistant. Instead, I adhered the tiles with heavy duty construction adhesive. That dried for about 3 hours, then came the tedious work. I used a white 100% silicone caulking for windows and doors and filled all the lines in between the tiles, and used soap and water to clean the overfills off the tiles and wood.
*A helpful hint* When you buy a whole tube of caulking and don't use it all, to keep it from drying out just wrap a small piece of duct tape around the end and make sure it seals all air holes off.
After all the caulking dried overnight, My hubby drilled the holes for the silver cabinet knobs on either side for me, and it was finished!
I also took the left over tiles I trimmed off the edges, made them into square designs, and hot glued them onto sticky back felt squares! Now I have matching tile coasters! these colors also match our new kitchen colors you can see here!