[michaelt]

Merely that a coating that retains total choice in colours is more flexible than one that limits the range of colours possible.

And presumably that's part of the contribution here - a nonstick toilet that doesn't look like the ones you get on planes and trains already.

Also, the current fashion in my country is for white toilets - you go to a bathroom showroom, ~95% of what's on display will be white. A design that doesn't require a change in fashions is simpler than one that needs tastes to change.