For the inner problem I would just bring it up to size with more of the background fabric. I think it breaks up your design too much to add a different color in there.

i like the border and inner border to be the same as the mariner's background

I would go with the border around the compass being either the same the background of the compass or else the light tan, but I'm thinking the darker would be better. Also I would just do echo quilting on the background of the compass and leave the border area plain. Then do whatever you are wanting to do on the rest of it. I think the tan outer border would look best even though I usually prefer a darker border.

Everyone - thank you! I didn't consider using the darker brown as a border for the compass, but I think that would work well. Especially since I have the boat name embroidered with the dark brown color. I love the peach color behind the compass (Actually, I love a lot of the materials I used, especially the paler blues. That's a surprise to me. I usually go for brighter stuff.) So I am going to do the outer border with the peach. I now have a direction and can get back to the machine!
BTW, the boat cushions are in teal and green, which is why I was thinking about the teal border, but I'm ditching that idea! Oh yes, it's a boat, so I'll 'scuttle' that idea.