Hi
I was working on Altium Designer V6.5 but I updated it to 6.8 and then I saw that when highlighting nets with the panel at top right of screen other nets aren't colored and it is difficult to recognize top or bottom layer tracks. because they are all gray scale ant not colored. but I am not in single layer mode or monochromes or gray scale mode .
thank you.
@ltium DESIGNER V6.8 ----BAD PROBLEM WITH MASK OPTION----
alternatively you can use ctrl + left mouse click on net will highlight that net. use the same combination key on blank area to highlight all nets. Same as Shift + C