The sprite is the adult dragon. It's a description I've heard tossed around about pixel pet adoptables. If it's "sprited well" it means drawn pretty. If it's a "sprite," it's the ultimate form. If the male and female "sprite differently," it means that there's a different final form for each gender.

"This egg matches the weather outside" is the seasonal dragon. This time of year it's spriting as autumn.

As for "white with a pink tail," do you mean this one?

(http://dragcave.net/viewdragon/n/Destai%27s%20Star%20of%20Vengeance)

That's the female vampire. The male and female are sprited differently. The male is black like yours, and the female is white.

My silvers have also been prolific, and I could breed you one of those too.