A tip:
If you already own a chocobo, try looking around for "Bottle Of _____ Bottle Of Black Chocobo Dye".
Like this one http://www.ffxiah.com/item/2383/bottle-of-black-chocobo-dye
There are one of each color. Use it once it forever stays (until you decided to switch another chocobo to your Chocobo Whistle)
Get dye via 75 Chocobucks, win bucks by racing.
Hopes this help.