Here is the history of Kenya flag. The Kenya flag (Swahili: Bendera ya Kenya) was officially adopted on December 12, 1963. The Kenyan flag is based on that of Kenya African National Union.
The colours symbolize black majority, red for the blood shed during the struggle for freedom, and green for natural wealth; the white fimbriation was added later and symbolizes peace. The black, red, and white traditional Maasai shield and two spears symbolize the defense of all the things mentioned above.
The colours of the flag have been specified by the Kenya National Archives.The Kenyan flag is based on the black over red over green flag of Kenya African National Union (KANU), the political party that led the fight for freedom and independence of Kenya. Upon independence, the white fimbriation, symbolizing peace and unity, and the shield was added.