I think the stoplight colored family of echinos are all very good looking. With that in mind, I'd have to say that your echino is going to be good looking, but it is not the "True" Watermelon.
I'm not going to get into the whole lineage argument, but I have seen all of these echinos first hand. I have seen the Rastafari at tubs's house. I saw the Goledn Eye at Aquascene's store, and I saw both the Red and Pink Watermelons in Hugo's house. BTW, Hugo originally purchased the Pink Watermelon from Clint Conway.
The one thing you notice when you see the "true" watermelons is that they fluoresce so brightly that they are almost to hard to look at. Thos pics above aren't Photoshopped. They are really that intense. When you first see them, you can't believe a coral can "glow" that intensely.
I have seen enough nice coral to make reefer's eyes bleed, yet when I saw my first "true" watermelon (a 1/4" frag at tubs's house), I was astonished. He pulled it out of the bottom of the tank and held it out of the water and it was more intense than a highliter pen.
I don't own any of the "true" watermelons, although I wish I did. I do own the other stoplight variants. I passed up a couple of opprotunities because my tank was still recovering from a recent move, but if I wouldn't pass up the opprotunity to buy a frag in person again. It's that nice.
Both Watermelons are intensely colored, perosnally I prefer the red watermelon myself, but the pink one glows more intensely.