A loaf by any other colour

We all take it for granted that bread may be purchased either as a white or as a brown loaf. But what if it could be red or blue? You might say that such a colour would have to be artificial and would therefore be unacceptable. On the other hand we constantly demand that the food manufacturer puts colouring into foods before we will buy them. For example, the yellow of smoked fish, the additional orange colour added to many orange squashes, or the reintroduction of artificial colour to make good that lost during processing, such as the loss of colour due to the use of sulphur dioxide as a preservative. Since we not only accept but demand the colouring of foods, why should we be limited to only those colours that may be considered as exaggerating or restoring an existing colour?