Something you don't think you need until you see it.
The font size in the Administration Menu is 9pt, too small for my liking (your eyes, you mean - Ed).
To change it edit the file //sites/all/modules/admin_menu/admin_menu.css and change the font size. I prefer 12px.
One of my pet hates on the web is grey on white fonts. They really annoy me, perhaps my eyesight isn't that good. For 600 years since Gutenberg mankind has been fed a healthy diet of black fonts on a white background, and all of a sudden the last twenty years has seen web page designers using grey and other pastel colours on a white background.