Capsule and Pill Color Measurement

Color is the most fundamental part of a drug's personality with the unique ability to create emotional appeal, communicate functional values and benefits and distinguish one brand from another. Today's gel caps boast over 80,000 color combinations, and continuous advancements in technology consistently bring new and colorful coating products to market. HunterLab understands the Pharmaceutical Market's need for precise color measurement of tablets, caplets and capsules and has been providing color measurement solutions for the pharmaceutical industry for over 60 years. Many of the world's leading pharmaceutical manufacturers rely on HunterLab solutions to ensure the quality and consistency of their products that their customers expect.

Test Color of Pharmaceutical Capsules

Tablets, capsules and caplets come in a multitude of shapes, sizes and colors. They can be opaque, translucent and transparent. Accurate color measurement requires not only the right instrument, but the right sample holders for accurate and consistent sample presentation. HunterLab provides a wide selection of sample holders and can customize for your specific application. The preferred instrument type will largely depend on the sample type:


Measure Color of Pharmaceutical Capsules

Opaque Liquids are impenetrable by light and are best measured using Directional 45/0° reflectance geometry. This is the geometry that most closely matches how the human eye 'sees' color.


Translucent Liquids allow light to pass through, but only diffusely, so that objects on the other side cannot be clearly distinguished. Both reflective and transmittance measurement modes may work well depending on the translucency of the sample. As a rule of thumb,

  • If at the path length that your customer will view the sample, you can see slight details of your thumb or finger through the liquid, then transmittance is the preferred measurement method.
  • If you cannot see slight details, then reflectance measurement using directional 45°/0° is preferred, though it is also possible to use diffuse d/8° sphere geometry.
  • Path length is defined as the thickness of the sample from where the light enters to where it exits the sample. A simple test to determine the translucency is to pour the liquid into a clear container that simulates the thickness that the sample will normally be viewed, and hold your thumb on the back of the container and look through the sample.

Transparent Samples allow light to pass through with little or no interruption or distortion so that objects on the other side can be clearly seen. These plaques can only be measured using transmission instrumentation.

Many of HunterLab's spectrophotometers are versatile enough to accommodate most applications of color measurement. However, based on 60+ years of experience and a thorough understanding of our customers' needs and product use, these particular instruments are most suited for this industries application.

LabScan XE (Directional 0°/45° Geometry, Reflectance, 400-700 nm)

10% of HunterLab customers select this instrument for its large 44 mm (1.75 inch) measuring port, and for its level of sophistication, simplicity and versatility.

Test Color with LabScan XE

UltraScan PRO (Diffuse d/8° sphere Geometry, Reflectance and Transmittance, 350-1050 nm)

30% of our customers select this high performance instrument for its extended wavelength measurement and its ability to measure both reflected and transmitted color.ultrascan-pro-spectrophotometer

Measure Color with UltraScan PRO

UltraScan VIS (Diffuse d/8° sphere Geometry, Reflectance and Transmittance, 360-780 nm)

30% of our customers select this instrument for its extended wavelength measurement and its ability to measure both reflected and transmitted color of samples that are transparent to opaque.

Test Color with UltraScan VIS

If you are unsure which instrument type is right for your samples, please call or email HunterLab technical support and we will be happy to assist you in making the proper instrument selection.

AN 1001 ALPHA

Measuring the Water Whiteness of Liquids Using the APHA Index

Measuring the Water Whiteness of Liquids Using the APHA Index.

AN 1002

CIE Standard Observers and calculation of CIE X, Y, Z color values

CIE Standard Observers and calculation of CIE X, Y, Z color values.

AN 1003

Color Measurement on Very Small Samples

Color Measurement on Very Small Samples

AN 1005

Measuring Color using Hunter L, a, b vs CIE 1976 L*a*b*

Measuring Color using Hunter L, a, b vs CIE 1976 L*a*b*.

AN 1013

Averaging in Color Measurement

Averaging in Color Measurement.

AN 1018

Using Hitch Standardization on a Series of Color Measuring Instruments

Using Hitch Standardization on a Series of Color Measuring Instruments.

AN 1031 Identification of Measurement Parameters

Identification of Measurement Parameters

Identification of Measurement Parameters.

AN 1033 Color versus Appearance

Understanding the difference between measuring color and measuring appearance

Understanding the difference between measuring color and measuring appearance.

HunterLab Solution Matrix

Geometry, Measurement Modes, and Indices

Geometry, Measurement Modes, and Indices.

MM 5008 Measuring Opaque Liquids with ColorQuest XE

Measurement method for opaque liquids using the ColorQuest XE, UltraScan PRO, UltraScan VIS.

MM 5033 Measuring Opaque Liquids with UltraScan VIS

Measurement method for flat, opaque solids using the UltraScan PRO, UltraScan VIS, or ColorQuest XE.

MM 5058 Measuring Opaque Liquids with UltraScan PRO

Measurement method for flat, opaque solids using the UltraScan PRO, UltraScan VIS, or ColorQuest XE.