orange and blue names in file list

What does it indicate if the filenames in the file list turn orange or blue?

Orange, it seems, indicate that the file extension will be changed by application of the chosen methods. Do I have that right?

I can't figure out what the blue coloring means.

Details are in the Error column of the list.

Grey: Filename unchanged
Black: New filename
Orange: Extension changed
Blue: Identified as a "pair" of another file (only if "Pair renaming" is enabled)
Red: Error - file wll not be renamed

Reply to #2:
Thanks!
Reply to #3:
saçmalama aq