Many times the bias of the colour scheme you use in your art or photography determines the mood of your piece.
Cool colours can have a calming effect. They can also be comforting and nurturing. Think of blues, greens, turquoise, and purples that lean towards blue.
Warm colours can create excitement and energy and optimism. Think of reds, yellows, pinks, and oranges.
I used a picture of blossoms on one of my garden shrubs to convey two very different moods using either warm or cool colours.
Which do you prefer ? How do you use colour in a deliberate way to convey the mood you are trying to create ?