Because the messenger pigeons are normally blue pigeons
In earlier days blue pigeons used to bring and take messages. So, bells were tied to their feet so that their owners could identify them from the bells tied on their feet.
blue or clear
Blue
You would get blue-green.
It would still look blue :)
BLUE
Blue
Blue Bells Model School was created in 1980.
blue
BLUE
Blue Bells Model School's motto is 'Be Honest, Be Brave'.
Green is a secondary colour made up of equal parts Yellow and Blue. Blue is a primary colour. When you mix a secondary colour with either of the primary colours it is made up of, you get a tertiary colour. In this case you would get Blue-green.