For some reason when Im breeding the chocobo they never turn out blue just green and yellow, Ive read alot of stuff on the internet concerning the topic but to no avail. Refresh my memory how do I get a blue chocobo?

Sadly, chocobo breeding in FFVII is notorious for being something of a hit-and-miss affair in regards to gaining the desired result. A large random factor comes into play when breeding your pairs together to create the coloured ones, but you're already halfway there (as you've bred a green one already). Just keep mating your pairs and eventually, you should hopefully get a blue one. If you've been racing your chocobos at the Chocobo Races in Gold Saucer, their Class rank has a large bearing on the likelihood of getting a desired coloured chocobo after mating them as well - the higher the rank, the better the odds of getting a blue or green one (with S rank being the best for this).

A handy trick to use to help speed up the process is to save the game just before mating your chocobos, as if you don't end up with the desired result, you can simply reset the game and try again (as it's random which type of chocobo you end up with). Just make sure that when you get a blue chocobo, that it is the opposite gender to your green one, as you have to mate these two to produce your Black Chocobo (chocobo incest not withstanding). ;)