To say "give no quarter" means to show mercy, take no prisoners, death to all who challenges. A visual of no quarter is a red flag (usually with you insignia on it). A flag of no quarter was flown by Sgt. Santa Anna at the Alamo.
There are more than one flag but the colours for the most used Serbian flag is Red, Blue and white. Red meansDanyisim, sacrifice fighrt/war. Blue means: nature, sky, land and water. White means freedom