Lion Safari's enabled and disabled button contrast is so low it's hard to see the difference

Is it me or is Lion's buttons' contrast way too low? The back button (enabled) and forward button (disabled) are almost the same shade of gray.

Is there a way to increase the contrast between enabled and disabled? I tried System Preferences - Universal Access - Display - Enhance contrast, but it doesn't really enhance the contrast of the button.

Nope, sadly, there is no UI control for changing such contrast. You'd have to play within the app's insides and it may cause problems down the way, and might have to be done every time the app is update. Therefore, much less trouble to live with it than change it. :-)