These are an all-natural product and therefore color and sizing may vary from chew to chew.
 
The key is the right size for the right dog !
A chew should last for hours and even days but as it is an expensive treat people tend to downsize the chew at first to try it but that is a mistake. Most Large dogs will chew it in a few days while Medium and Small dogs will take more time to chew it (it can last weeks).
It also depend on your dog’s chewing habit and there are exceptions with a few breeds which naturally have stronger bite strength (Amer