Her black hair shone bright in the yellow sunlight of the day. I know, boring. Now try this. Her sleek raven hair shimmered in the pale, lemony yellow sunlight. What is the difference beyond using different words? It is the fact of giving the reader more by describing the shade of the color. Rather than a simple phrase about her black hair, we now know it is the color of black found on a raven. The sunlight is no longer simply yellow but now we are aware that it is likely an early morning sun, diffused by the morning dew, giving it a softer, yellow than if it were the noon-day sun.
Try this little exercise; write down the basic colors. Black, red, yellow, green, blue, purple, white, orange, and perhaps pink. Now, describe these colors to a blind person who has never seen color. How will you evoke an understanding in that person as to what the color black is? Not an easy assignment, I am aware, as I have already done this years ago.
You will discover that unlike with a person who has seen and knows colors, you cannot reference another color to describe, say, orange. You must reach deeper into your ability to describe to bring forth an appropriate response of understanding. Difficult but not impossible.
To help you get started with an easier task, I will give you some other words to help describe some basic colors,
Blue: lapis lazuli, sapphire, cobalt, chalcedony
Black: obsidian, coal, raven, onyx, jet black
Green: lime, pine, olive, emerald, jade, khaki
Purple: eggplant, amethyst, violet
White: egg white, antique white, ivory, cream
Red: crimson, ruby, wine, scarlet, burgundy
Orange: tangerine, peach, melon, pumpkin, carrot
Pink: petal pink, magenta, carnation, flamingo pink
Yellow: lemon, gold, Chinese yellow, goldenrod, khaki
Now, go forth and find many more shades of each of these colors and use them to help you in your descriptions of hair, eyes, clothing and much more.