Real World Comparisons:
Pacific Blue Tang Fish
The blue screen of death
Shades of Blue:
Azure, periwinkle, turquoise, aqua, sky, robin's egg, cerulean, cobalt, indigo, navy, royal, sapphire, teal, ultramarine, powder blue
Make every detail count
Colors are powerful descriptors, not fillers. Make sure that if you use a comparison or contrast to highlight a color, you choose the right one. Look at the setting and atmosphere you are working to create, then draw from the viewpoint character or narrator's history, education and past experiences to find the right fit.
A poor example:
We reached Alber too late--his eyes stared ahead, glassy and unseeing, and his lips were blue, as if he had chugged a bottle of Scope only moments before expiring.
What's wrong with this example?
This lends a comical twist to the description which spoils the result of death. As well, while (most) mouthwash is blue, it doesn't lend a staining effect to the things it touches.
A strong example:
We reached Alber too late--his eyes stared ahead, glassy and unseeing, and his lips were blue, as if he had eaten a handful of ripe blueberries only moments before expiring.
Why is this example better?