If you want bar numbers to be clearly distinguished, you can enclose them in a rectangular or circular enclosure. You can change the bar number enclosure type in each layout independently of other layouts.
For example, you can have bar numbers appear with different enclosures in full score layouts compared to individual part layouts.
Procedure
In Setup mode, choose Setup > Layout Options.
The Layout Options dialog opens.
In the Layouts list, select the layouts in which you want to change the bar number enclosure type in one of the following ways:
Click Select All.
Click Select All Full Score Layouts.
Click Select All Part Layouts.
Click Select All Custom Score Layouts.
Ctrl/Cmd-click individual layouts.
Shift-click adjacent layouts.
By default, the layout currently open in the music area is selected when you open the dialog.
Select Bar Numbers from the Category menu.
Choose one of the following options for Enclosure type:
None
Rectangle
Circle
Click Apply, then Close.
Result
Bar numbers in the selected layouts are shown within your selected enclosure type. The size of the enclosure is relative to the font size of the bar numbers, but the size and shape of the enclosure are also determined by your padding values.