Women have a clear preference for cool colors, Natalia Khouw noted. Men are generally more tolerant of black, white and gray than women. You can test how color-blind visitors will view your color scheme by converting it to grayscale or black and white. For the color-blind, What Color is a tool for identifying RGB value as well as the color name. So a designer can use warm colors for emphasis and cool colors to minimize emphasis.
Brighter colors attract our eyes first, and if overused, can cause visual confusion.
Overusing a bright color as an accent reduces its effectiveness. Emotional responses influence color considerations, and differences in color value and intensity can evoke very different emotional reactions. Light red is associated with cheerfulness, but bright or dark red can induce irritability. Light yellow-green is associated with freshness and youth, but the darker shade olive is associated with drabness and decay. Light sky blue is associated with tranquility, but the deeper value indigo is associated with depression.