Macro shots do make it hard to see what the spectrum of lighting is, though to be honest the ones that aren't corrected give you the least idea of actual color in many cases and are the least impressive to me. If it's all washed out in blue, about the only thing that will come through is neon green or orange and maybe yellow. That doesn't tell you anything about the other colors in the coral and it might look way better in a more color-balanced lighting. Again, this has to do with what we perceive with our eyes since our brain does the correction automatically, and what the camera can do (no brain). If there is some background in the picture, you can often pick out other objects and judge by that how skewed the color may be. If everything around it looks blue, then it was likely not corrected, but this does not mean it was taken under non "normal" lighting; that could be 20K daylights for that person. Granted, there are a lot of other things that can be done besides WB correction with some programs, but hopefully in most cases the photographer is trying to adjust to give a true representation of what they see with their eyes, and not just make it look better than life. Not always the case, I know.
I think macro pictures can be fun to see details and things, but they should be accompanied by a wide shot to see the whole piece if possible. Sometimes a frag is all a person has, so...
In your case, where the macro shot made the eyes look larger and more impressive, that does stink and that's a good example of when a macro alone is not really a fair representation. It's hard to get a feel for scale, and that stinks, but, that could be a lesson for you. Don't buy based on a macro alone.
