So I was thinking about this some - it's really difficult (even with the brackets in the other screenshot) to distinguish between both:
a) The selected letter to the rest of the symbols
b) The page numeric page selectors from the rest of the symbols
So what I suggest is toying around with putting a more eye-catching background colour around the selected letter (and maybe a more eye-catching foreground colour on the letter itself), and then stretching those colours behind the numeric page selectors as well.
Can you experiment with that and show us what that might look like?
