I consider High Shine silver as Platinum. The "snow white" platinum ones are tyrosinase-positive leucistic. Those have a smooth clean white look. The "high shine" platinum I have (cheaper ones) are tyrosinase-negative leucistic.
Here is an example for a "snow white" platinum silver arowana aka tyrosinase-positive leucistic: http://imageshack.us/photo/my-images...50872.jpg/sr=1
Basically, "Snow White" platinums are more rare and expensive compared to the "High Shine" platinums. Hope this helps clear things up.
Here are photos of my "high shine" platinum: