From mailing list:

> (2) NetBeans tab switches are too "roundy" comparing to Mac
>
> (3) color of inactive selected button is darker gray on Mac, but lighter blue
on NetBeans
Would be easy enough to fix.  The NetBeans tab control bridges attributes of a
window title bar and tabbed panes and buttons - but with the exception of
buttons, none of the above are as round as ours.   You'd make the changes in a
class called GenericGlowingChiclet ("chiclet" was a kind of chewing gum) in
core/swing/tabcontrol.