Reds
One of the loudest and most vibrant colors is red. Often associated with fear, anger, sexuality and excitement, the sight of red can cause a slight increase in blood pressure, "hyping up" your body by affecting its adrenal glands. Alternatively, red can also pertain to strong emotions considered positive, such as confidence, power and courage.
Blue
Countering the powerful and strong color red, blue provides a response on the opposite end of the spectrum. Blue's location at the short-end of the visible spectrum is the exact opposite to red, located on the long-end of the visible spectrum. The site of blue can help lower blood pressure. Blue also evokes physiological responses and emotions related to security, trust and dependability.
Bright Colors
The overall effect of bright colors is one of happiness. Colors such as yellow connect with emotions of optimism as well as inspiration. Orange, like yellow, produces energetic emotions; gold tints bring about a feeling of prestige. White represents feelings of security and comfort.
Dark Colors
Shifting a bright color to a slightly dark color -- such as orange to dark-orange -- can reverse its meaning. Whereas orange is optimistic, dark-orange evokes insecurity and distrust. Although many dark colors produce negative emotions, others, such as blue, create a feeling of trust. Dark purples create feelings of sadness; black produces fear.