Rastafarian

I just wanted to ask, what does it mean to be a rastafarian.... maybe i should have googled it, but just thought id come and ask on here first... if any rastas are out there.... what is up with the colours Yellow, red, green , black, i use to know a poem when I was at school... Red is for the blood that runs through the veins, yellow for the sun that shines in the sky, green is for the dope we smoke to get high, black for Bob Marley, no woman no cry.....Is that what the colours really represent.