Speaking of visual communication is not possible without a general discussion on the colors. The colors are part of our life we communicate messages, stimulate our feelings and affect our emotions.

RED: it has a visual impact, causes a stimulation which increases heart rate and blood circulation. It's exciting, but also is the color of danger.
Positive meanings: passion, energy, love, strength, action.
Negative meanings: blood, war, danger, aggression.

YELLOW: is the color that reflects more light, is therefore influenced by the context that surrounds it. This feature makes the instability associated inconstancy and betrayal.
Positive meanings: sun, light, summer, gold, optimism, helpfulness, unselfishness
Negative meanings: sickness, cowardice.

BLUE: is associated with purity.
Positive meanings: stability, peace, unity, contentment, harmony, loyalty, sky and sea.
meanings negative depression, conservatism, loneliness.

WHITE: represents purity and goodness.
Positive meanings: snow, purity, innocence, peace
Negative meanings: cold, hospital, infertile.

BLACK:
Positive meanings: power, formality, depth, elegance, style
Negative meanings: death, anonymity, wickedness.

GREEN: is the color that recalls the nature, communicates freshness and cleanliness.
Positive meanings: nature, spring, fertility, money, perseverance, promptness
Negative meanings: envy.

ORANGE: is the combination of red and yellow. Notify light, joy, freshness, energy and joyfulness.
PURPLE: is the combination of red and blue. Seems not to communicate specific feelings, and is complicated in the communications field.

PURPLE: is the combination of red and blue. Seems not to communicate specific feelings, and is complicated in the communications field.

GREY:
Positive meanings: intelligence, dignity, maturity
Negative meanings: shadow, boredom, depression.