I got intrigued so I googled some Russo White Diamonds..
Most pictures I come up with do show a colored stripe or splotches along the back. However, there seems to be less color on them, then on yours..
You would have to make some better pictures on a dark back ground with some good light (no flash though or over bright).
This adult White Diamond has color, too
http://nicebalz.com/image/data/collectionsnake11.jpg