"The first stab of love is like a sunset, a blaze of color -- oranges, pearly pinks, vibrant purples..." - Anna Godbersen

Pink and purple sunsets bring a sense of peace and calmness. This makes sense because cool colors (pink, purple, blue, etc.) usually give a soothing impression. Artist and photographers take or draw pictures with these colors to hopefully give other people the same sense of calmness they felt when they took or drew the picture.
Not very many people take the time to see and enjoy the feeling a sunset gives. The beauty isn’t just in pictures. It can be found everywhere if someone just takes the time and look.

More information about colors http://www.tigercolor.com/color-lab/color-theory/color-theory-intro.htm