资料题：It can be concluded from the passage that（　）。

Manufacturers have discovered by trial and error that sugar sells badly in green wrapping,that blue foods are considered unpalatable,and that cosmetics should never be packaged in brown.These discoveries have grown into a whole discipline of color psychology that now finds application in everything from fashion to interior decoration.Some of: our preferences are clearly psychological.Dark blue is the color of the night sky and therefore associated with passivity and calm, while yellow is a day color with associations of.energy and incentive.For primitive man, activity during the day meant hunting and attacking, which he soon saw as red, the color;of blood and rage.So it was natural that green,the complementary color to red, should be associated with passive defense and self-preservation.Experiments have shown that colors, partly because of their physiological associations, also have a direct psychological effect.People exposed to bright red show an increase in respiration rate, heartbeat, and blood pressure; red is exciting.Similar exposure to pure blue has exactly the opposite effect; it is a calming color.Because of its exciting connotations, red was chosen as the signal for danger, but closer analysis show that a vivid yellow can produce a more basic state of alertness and alarm, so fire engines and ambulances in same advanced communities are now rushing around in bright yellow colors that stop the traffic dead.