In a longitudinal wave, the motion of the medium is parallel to the direction of the wave. This means that the particles move left and right which in turn makes the other particles start to oscillate.
The UNIA founded by Marcus Garvey has a constitution which defines red, black, and green as the Pan-African colours: red representing the noble blood that unites all people of African ancestry, the colour black for the people, green for the rich land of Africa..
A 1920 map shows the races of the world classified by color: White (shown colored red), black (shown colored gray), yellow, brown, and red (shown colored light orange) (It was understood that Amerindians were the red race.); areas of mixed black and white populations are shown as purple.n the 2000 US Census, the black race, also called African American on the US Census, refers to a person having origins in any of the Black racial groups of Africa.. The other three races are not labeled by color.