Because there is no blue colored food in the nature. Blue color can easily determined in the case of contamination inside of the product/process.
what about blueberry? is not it blue?
Hi Honour; Blueberry is not actually blue. As you can see from the attached picture blueberry has navy blue color around of it and when you mash it,it becames purple !
The blueberry juice color depends on the pH of the medium. In acid medium it is more red and in basic medium it is more blue. You can test it by neutralizing the juice (which is normally acid) with baking soda.
think it should be phosphorus orange
as a different point of view, maybe blue is one of the few colors that even color blind people (especially the green-red type ones) can discriminate from the other colors in every light conditions. I know from myself As it is stated earlier, bluish colors are not common for foods. Considering almost 10 percent of the population is color blind, this point might be important.
Dear Gökhan…very good information i did not think in that way…