Redman, that's a female bluejaw. The easiest way to tell it's not a Sargassum, is the color of the body dots. Sargassums are black, Bluejaw's are that light blue color. The dots is also a good way to tell it's not a Crosshatch, because they don't have them at that size, but do have the "X' pattern. Also, even as juvi's, the cross's still have a full female tail coloring, before either becoming a full female or turning male. Here is a small juvi Crosshatch (notice how big the eyes are compared to the body):
As far as coloring on Sargassums, from what I've found, as they gets over a certain size, the coloring (the red tail and check stripes), began to dull. Also over 100 images, there were no different in coloring, other then the slight differences based on size. Here are a couple whooper Sargassums I found:
