No, of course they're not. But The Rules are The Rules and one is not allowed to question The Rules or ask why The Rules exist. Because they are The Rules.
The rules are for the reason I explained, increased surface area. The coloured tread is because two different compounds are used and the grip is not the same. And why you should not be riding Michelin tyres.
No, of course they're not. But The Rules are The Rules and one is not allowed to question The Rules or ask why The Rules exist. Because they are The Rules.