Color Targets for Consistent Color
If getting color accurate is essential–to match the colors in a company logo, for example–then use a standard color target.
For normal photography, the two most valuable are the Kodak Gray Card and the GretagMacbeth ColorChecker shown here. Their colors are known quantities, and so they can be used to judge and correct your captured colors. At the very least you can use them for visual reference, but the ColorChecker has the more valuable function of helping to create ICC camera profiles. Under highly controlled conditions, such as fixed studio lighting setups, some lighting manufacturers recommend using an IT 8.7/2 target, which is normally used for scanning.
Based on the Munsell ...