On OS X it the default button is dark blue (and in other apps that support widget animation) pulsing. On Vista the default button gets a light blue glow. XP just adds a blue line around the edge of the default button (with Luna), etc.
On OS X it the default button is dark blue (and in other apps that support widget animation) pulsing. On Vista the default button gets a light blue glow. XP just adds a blue line around the edge of the default button (with Luna), etc.