It's important to have colour in writing. Dullness just gives your reader another reason to go elsewhere, and few of us have the luxury of a tied reader.
But what is colour, and will any hue do?
The answer is no. Think decor and you will get the general idea of what is good and what isn't:
- colour should highlight and not obscure: the more people notice the colour, the less they notice your theme. Don't overdo it and you will attract the right kind of attention.
- choose well: a little bit of thought can bring out a phrase or description that's a good fit and says something about you. Pick up the obvious roll of woodchip or pot of magnolia and you'll do your writing a disservice.
- try not to mix your decoration too much: a bit of coordination between the images you use or the similes you employ can give nice balance to a piece's readability. Try it and see what happens.
So, no colouring by numbers. Look for opportunities to add something extra to what you write and you will make your writing your own.