The Pan-Slavic colors, red, blue and white, are colors used on the flags of most Slavic states and peoples. Their use symbolizes the common origin of the Slavic peoples. They were first used on and originate from the Flag of Russia.
The flag of Bulgaria also originated from the same Pan-Slavic colors, but the blue was replaced with green, because Bulgaria was developed as agricultural country after its independence in 1878. The flag of Montenegro also consist of the same colors, in order as the flag of Serbia, but its blue color is brighter. The flag of Eastern Rumelia, a former Turkish province now part of Bulgaria, also consisted of the same colors.