The Munsell System

One of the most commonly used color determination systems is the Munsell system (Fig. 3a).^7,28 It was introduced by Albert Henry Munsell in the early 1900s. The 3 main components of color as per the Munsell system include hue, chroma, and value (Fig. 3b).^7,28

Fig. 3a - Munsell color chart

Fig. 3a - Munsell color chart

Image: Vejdemo-Johansson M et al, CC-BY-4.0

Fig.3b - The three determinants of color as per the Munsell system

Fig.3b - The three determinants of color as per the Munsell system

Image: Jacob Rus, CC-BY-SA-3.0

Hue

Hue represents the dominant wavelength/s of light (in the visible spectrum) reflected by an object.^4,7,28 It is the result of both physiological and psychological interpretation of a combination of wavelengths. It is the term by which we identify a color such as red, yellow, green, etc.⁷ Hue differentiates one family of color from another (Fig. 4).^7,28 Hue is denoted by letters A, B, C, and D on the commonly used Vita classic shade guide (Fig. 5).

Fig. 4 - Green, orange, yellow, and blue-hued objects

Fig. 4 - Green, orange, yellow, and blue-hued objects

Fig. 5 - Hue denoted by letters A, B, C, and D on the commonly used Vita classical shade guide.

Fig. 5 - Hue denoted by letters A, B, C, and D on the commonly used Vita classical shade guide.

Chroma

Chroma or saturation is defined as the intensity of a hue, the strength of the hue, or the concentration of the pigment (Fig. 6a).^4,7,28 Chroma and value are inversely proportional; as chroma increases, value decreases (Fig. 6b).^4,7,28 Tooth chroma decreases with bleaching and increases with aging.³¹ Optimal illumination in the dental operatory is required for assessing subtle variations in hue and chroma.⁴ Higher numbers on the Vita Classic shade guide indicate increased chroma (and decreased value).⁴

Fig. 6a - Chroma increases from left to right.

Fig. 6a - Chroma increases from left to right.

Fig. 6b - Chroma increases from left to right, while value decreases in the same direction.

Fig. 6b - Chroma increases from left to right, while value decreases in the same direction.

Value

Value refers to the relative lightness or darkness of a color.⁷ It is directly associated with the amount of light energy the object reflects thereby helping to assess its brightness.^4,7 The more light an object reflects, the higher its value; conversely, the less light it reflects, the lower its value.⁷

In the Munsell system, value is categorized on a white-to-black grayscale.^4,7,28 Objects with a higher value have less gray; conversely, objects with a lower value have more gray and appear darker.^4,7,28 Value has ten gradations; a value of 0 indicates a black/dark object, while a value of 10 indicates a white/bright object.³² The value of natural teeth ranges from 5.5-8.5. Value is the most important determinant in shade selection.³³ If the value is matched accurately with the adjacent natural teeth, small variations in hue and chroma are not easily discernible.³³ Restorations that are too high or too low in value (Fig. 7) are easily detected.

Fig. 7 - Restoration on tooth #8 has a lower value (is darker) compared to the adjacent and opposing teeth

Fig. 7 - Restoration on tooth #8 has a lower value (is darker) compared to the adjacent and opposing teeth

The following characteristics are true regarding value:

• Value is the only dimension of color that can exist by itself. ^34,35

• Objects of different hues/chromas may have the same value.³⁶

• Value just like color is affected by its surroundings, lighting conditions, and the observer’s perception.³⁷

• Increasing the surface reflectivity and decreasing the chroma are two methods of increasing the value.⁷