Understanding the Meaning of Colors (Color Psychology) is important for your pictures.
And altough the meaning of colors varies depending on culture and circumstances each color has many aspects to it.
Color is a form of non verbal communication a dynamic energy. Use colors wisely in your photography.
Learn the “language of colors” using the color wheel: Contrasting/competing colors, harmonic colors, warm and cool colors, etc…
Find detailed info about Red, Orange, Yellow, Green, Blue, Purple, white & Black here:
Another good & Quick guide for the use of colors and their meanings: