One of the great things about OmniFocus is the way in which the appearance can be customised at the drop of a hat. You can adjust almost everything about the Mac app, including font sizes, background colours, shadings, text colours and much else.
It is also childishly easy to install complete a theme created by someone else. The result that your own OF is changed completely within seconds.
I did this today when I read Stephen Hackett had spent some hours titivating his OF theme instead of spending time with the newly synchronisable Things (at last…..). Up to now I’ve been using one of Shawn Blanc’s themes, but now I’m torn between the two.