When is a "Pink" diamond - not actually 'Pink'???

All is not what it seems (allegedly) .... along with the many bizarre named synthetic gems (which we have to admit SOME are brilliant), the public are now faced with a new phenomena - coated diamonds - these are natural or lower quality man-made diamonds which have been specially coated in ["diamond" (sic)] the colour required (ie Pink, Blue, Red, etc).

But what is the problem? Natural (mined) Pink and Blue diamonds are much more expensive than their white counterparts - in the region of $100,000 to $250,000 per carat. If the subject diamond is 'coated' in the colour, surely the real value is almost the same as its donor diamond, after-all it is simply a coating? OK it may be a "diamond" coating but not through and through - just on the surface.

Our natural colour diamonds are not interfered with in any way, canary yellow is bright yellow and the 'Blues' range between Aqua and Sapphire.