A number of countries do: The Seychelles and also the Central African Republic.
It used to be Libya. However, the all-green standard has been replaced by the flag of the monarchy, which has green, white, black, and red.
I am pretty sure that the African loon has a green head and a white body.
Black, yellow, green, white, blue, and red
It's green and white.
Kuwait
The flag you are referring to belongs to the country of Guinea. It is comprised of three horizontal stripes in the colors of red, yellow, and green.
A country whose flag has the colours green, white and red
Black, Red. Green, Yellow, White
zimbabwe
The flag of the African Union is a green flag with the dark green map of the African continent on a white sun, surrounded by a circle of 53 5-pointed gold (yellow) stars.
Ireland.