Art and storytelling have very strong ties in my head. As a novelist I have to relay an entire story universe's spectrum using only words, and those are printed solely in black ink on white paper. I'm lucky in that I'm also a quilter and painter and amateur photographer, so I can draw on my knowledge of and experience with color from other sides of my creativity to assist in breathing color into my fictional worlds. Having myriad relationships with color helps, but all one absolutely needs as a storyteller is curiosity and the willingness to think in color when you're writing.
The way I've tried to expand my color sense when writing is to create character and story palettes first and consider inventive ways I can work them into my world. More than anything color palettes give me a creative nudge whenever my worlds and characters begin to fade into black ink on write paper.
Here's one of my more inspiring character palettes:
I built the palette using colors I wanted from four photographs and a painting of mine, some beads I'd bought from a lampwork artist, and combined them with an image of the character's body model. Once I assembled this palette I had a great visual resource to reference whenever I was character or world-building, and it also helped solidify innumerable details involved with my vision of the character; never a bad thing.
I'm not the only artist who does this, as I learned when I visited Roxy Radulescu's Movies in Color blog and saw the palettes she compiled from interesting movie stills. She's approaching it from the opposite direction that I do, in that she creates palettes based on finished creative works, but it's a technique that might work for someone who has little or no experience in building a palette from scratch for their world.
Do you have to create color palettes to be a great storyteller? Absolutely not. Your vision may be already fully colorized in your head, and you may have no trouble translating what you see in there onto the page. But if you do wrestle with depicting your story in color, and/or feel your world is a little too black-and-white, it doesn't hurt to give it a try.
(Movies in Color link swiped from Gerard over at The Presurfer)