Colour Tones

http://www.smashingmagazine.com/2010/01/28/color-theory-for-designers-part-1-the-meaning-of-color/

Warm Colors

Warm colors include red, orange, and yellow, and variations of those three colors. These are the colours of fire, of fall leaves, and of sunsets and sunrises, and are generally energizing, passionate, and positive.
Red and yellow are both primary colors, with orange falling in the middle, which means warm colours are all truly warm and aren’t created by combining a warm color with a cool color. Use warm colours in your designs to reflect passion, happiness, enthusiasm, and energy.

Red (Primary Color)

Red is a very hot color. It’s associated with fire, violence, and warfare. It’s also associated with love and passion. In history, it’s been associated with both the Devil and Cupid. Red can actually have a physical effect on people, raising blood pressure and respiration rates. It’s been shown to enhance human metabolism, too.
Red can be associated with anger, but is also associated with importance (think of the red carpet at awards shows and celebrity events). Red also indicates danger (the reason stop lights and signs are red, and that most warning labels are red).
Outside the western world, red has different associations. For example, in China, red is the colour of prosperity and happiness. It can also be used to attract good luck. In other eastern cultures, red is worn by brides on their wedding days. In South Africa, however, red is the color of mourning. Red is also associated with communism. Red has become the colour associated with AIDS awareness in Africa due to the popularity of the [RED] campaign.
In design, red can be a powerful accent color. It can have an overwhelming effect if it’s used too much in designs, especially in its purest form. It’s a great color to use when power or passion want to be portrayed in the design. Red can be very versatile, though, with brighter versions being more energetic and darker shades being more powerful and elegant.
I find the above article informative and helpful as I need to co-ordinate the colour palettes used on my designs to reflect the moods I want the images to portray.There are many elements to consider to achieve the right balance and harmony within an image.