There is a setting in the styles that allows for the current page to show up in a different color on the menu system.
This does not always work. I would guess that it only works about 2% of the time. There does not seem to be any consistency to the working/not working.
ALL my pages are in PHP always with a parameter, so they are called as:
/root/somwhere.php?par=1234
I have the color defined as:
"000000", // Current Page Item Font Color (leave this blank to disable)
"D0D0D0", // Current Page Item Background Color (leave this blank to disable)