Patterns and colors vary between specimens, certain catch locations can be more likely to have a certain characteristic, but you really never know what you're gonna get.
Kind of on the subject too is the fact the US sellers (online) don't really show you what you are buying. You get what they pick from the batch they have. I kind of like some of the Asian markets where they show you the actual online picture of the fish you are buying and depending on how 'nice' it is can also determine price you pay. I would be willing to pay a little more for the ability to actually pick my fish out.