As even my photos go, this is kind of shit (it was taken in a moving car), but I love the colours in it.
I really love colour, which might appear an odd statement, due to the fact that I wear mostly black. But I do: I love colour for what it's capable of. I love what it's capable of in art. Colour on people comes with a lot of styles and implications, so I tend to just ignore it in real life because I am that kind of person, but when it hits descriptions, I like to use those exact things to convey meanings about characters. Dress one figure in browns and faded reds, and you are able to convey a sense of earthiness, an individual who has simple, perhaps even honest principles, but with a hint for delayed violence. Likewise, using colour around the characters, for buildings and sky lines and whatever else you wish to pinpoint, allows you set a tonal point that conveys meaning to the reader as you shift for a different purpose. Of course, none of this is particularly surprising to anyone, but I'm just thinking aloud, so you'll have to excuse the basic storytelling notions that are being tossed round here.
One of the things I like to do with fiction is find a colour key for each story. It usually involves me finding a primary colour (sometimes two or three or all of them) and crafting a reaccuring image with it. That colour then begins to move around the story, turning into different shades of its primary, different images, and latching onto physical things that are linked to that colour. All of these then travel through the scenes together, drawing what is, essentially, an invisible thread throughout the story to link it together.
No colour is used for the same reason, same purpose, but generally speaking, it is either metaphorical or in the aid of tone. Within those two are hundreds upon hundreds of ways to use each differently, and that's really up to the author and, in some way, the reader. A lot of readers will take a device within a story and read it differently to what you, the author, intended, and what another reader may have read it as. I'm actually quite pleased when a reader comes to something of mine in a totally different way than I planned and still enjoys it.
Also, I'm always a bit disappointed when there's an absence of colour in art. At times it makes me think I'm in an empty, unfinished world, but rarely is that the point.