Effects of the color Blue
Blue invokes dreamlike states, it instills yearnings and has a calming effect, it leads to a serious inward outlook. Yves Klein's monochrome paintings can be seen along the same lines. Blue is the color of the heart and has a positive connotation. Unpleasant things of life, such as parking tickets, train tickets or the "blue letters" ("blaue Briefe" in German) announcing dismissal from work or not passing to the next grade in school are colored blue so they are accepted more readily.
Blue and red are the favourite colors of the Germans, which (together with its positive connotation) explains the frequent use of blue color in advertising. Blue color suggests cleanliness and freshness in household products such as detergents, blue drinks are cool and light.
The Blue Flower of Romanticism
The blue flower was a popular motif of Romantic poetry. The hero of Novalis' fragmentary novel "Heinrich von Ofterdingen" (1802) dreams of a blue flower instilling momentuous yearning in his soul. Novalis' poetic symbolism of the color blue is perceived by the reader intuitively: thinking of the color blue brings about a dreamlike yearning and produces both a feeling of calmness and of security.