Color theory primary colors work at all is that the imperfect pigments being used have sloped absorption curves, and thus change color with concentration. A pigment that is pure red at high concentrations can behave more like magenta at low concentrations. This allows it to make purples that would otherwise be impossible. Likewise, a blue that is ultramarine at high concentrations appears cyan at low concentrations, allowing it to be used to mix green. Chromium red pigments can appear orange, and then yellow, as the concentration is reduced. It is even possible to mix very low concentrations of the blue mentioned and
Orange (colour) of the carved pumpkins, or jack-o-lanterns, used to celebrate the holiday. People associate certain colours with certain flavours, and the colour of food can influence the perceived flavour in anything from candy to wine. Since orange is popularly associated with good flavour, many companies add orange food colouring to improve the appearance of their packaged foods. Orange pigments and dyes, synthetic or natural, are added to many orange sodas and juices, cheeses (particularly cheddar cheese, Gloucester cheese, and American cheese); snack foods, butter and margarine; breakfast cereals, ice cream, yoghurt, jam and candy. It is also often added to children's