Red - The 'base'. If asking for a black dragon, with red swirls on it, you would say, "I'd like it's base to be black, with red swirls." This dragon's base is red

Yellow(yellow, for those who can't see it X3) - Chest plates. These will vary, even from just male to female. They change a lot from version to version. But they are allways located on the chest, and down the stomach.
Dark Blue - You should know this... the eyes!
Purple - The "crest". This will also vary from dragon to dragon. But they will always be running down the dragon's spine (or sometimes on top of his head, and down to his spine, like in this picture.)
Green - Horns! These will also vary... But on MOST (not all) females, they have two sets of horns... one in the same place as the males, and one coming from their... cheek... area... Some females just have one set, like males.
Pink - Wings!! Like humans, dragon's wings have 5 'fingers'. on this image, four of the fingers are webbed, and the other is a sort of claw at the peak of the wing. Others will have different variations.
Light Blue (light blue) - The tail end.... I dunno what to call it X3 Other dragons have different tail ends.