Color is a direct consequence of the light. The visible light, considered as a set of electromagnetic waves of a length between 400 and 700 nm, is white. An object radiated by the light can behave in different ways:
It can absorb all the waves which constitute the light (black object);
it can fully reflect the incident light (white object);
it can absorb all wavelengths but one or some that are reflected and determine the color (colored object).
The human eye, thanks to special photoreceptors in the retina (rods and cones), picks up electromagnetic waves and converts them into an electric signal that can be transmitted and processed by the brain.
Color vision is not only a sensory event, but it creates a psychic process that first generates the feeling, with immediate effects and responsiveness, and then perception, a more complex experience derived from a synthesis of all sensory data collected.
The choice of colors for packaging applications is not a simple process and, on the contrary, it is important to choose with great care. Indeed, the message you want communicate passes mainly through color and color contrasts chosen. It is very important also the definition of markets and socio-cultural context, as the same color can have opposite meanings in different cultures.
Usually the methods to define colors are based on 3 or 4 primary colors, mixing at the right percentage, thus generating all the other colors. The most popular methods are the RGB model (primary colors are red, green and blue) and the CMYK (cyan, magenta, yellow and black).
Secondary colors are obtained by mixing the primary ones, and so on. The process continues until a complete chromatic scale is obtained.
Therefore, each color has a message. In European culture:
RED recalls elements like fire and blood, and is commonly linked to the passion. It attracts attention and conveys strength. An excessive use of this color is not advised because it induces perception of danger or error.
BROWN and its variants to the tones of terracotta are colors conjuring up nature and quietness, probably because they are linked to warm and earthy locations.
ROSA suggests sweetness, femininity, and with PALE BLUE, is often related to childhood.
ORANGE is a color that conveying energy and desire to communicate. It is a stimulating color to the observer, and it seems it induces appetite.
YELLOW is perceived differently depending on the background associated. It is often used by contrast, to avoid perceptions related to states of illness and disease.
BLU, in its various declension, is one of the most pleasing colors, reminiscent of the sea and the sky, it is linked to the concepts of calm and professionalism. Particularly suited to the idea of providing services, but less indicated in the food industry (as it reduces hunger).
GREEN recalls nature, harmony, reliability. It is a “go ahead” signal for the human brain, reassuring and is associated with biological food in the food and beverage context.
WHITE is a "non-color" associated with cleanliness, order and perfection, and creates a strong contrast if it is used for the background.
BLACK is associated with concepts of prestige, mystery, style. In combination with white, gold and silver creates the effects of great elegance.
The message you want to convey depends also by the combination of the colors. The use of analogous colors (neighbors in the color scale) is more delicate and can be associated with natural products; the combination of complementary colors (or opposite in the chromatic scale) generates a higher contrast, linked to products of impact.