Terms used to describe colour are often confusing and misused. To describe colours in the simplest terms, we need three definitions:

1. Hue - the tint, or the blend of red, blue and green that make up the colour.
2. Chroma - the saturation of the colour. For example, chroma is what makes a colour photograph different from a black and white photograph.
3. Value - the brilliance or brightness of a colour (the amount of grey).

Here are some suggestions that we have found make shade selection easier and more accurate:

• Avoid brightly coloured neck napkins. It's helpful to use a light blue neck cloth.
• Ask patients to remove lipstick or other obstacles, such as hats or scarves, which may affect the light.
• Schedule ceramic restoration appointments early in the morning to avoid eye fatigue.
• Take the shade before prepping the teeth.
• Pick the value first. Then pick the hue range.
• Fan the shade guide past the patient's mouth and pick the closest tab. Do not stare. Rest your eyes occasionally.
• Compare shades in more than one light, preferably one of them being natural light. Errors in value are most easily noticed in sunlight. Avoid fluorescent lights, which throw off the hue.
• Always cold sterilize your shade guides to prevent damaging them.
• Characterization should be clearly specified with a drawing.