What Difference Does Color Make?
By Mary Beth Watkins
This article originally appeared in the June 2011 hardcopy-only edition of the AAHP Network News.
What difference does color make? A lot, if it is a company logo, product label or even a raw material. Humans use color as key identifier for everything from finding our car in the mall parking lot to how much milk to add to our coffee. Color is critical to our perceptions of foods, clothes, and peoples’ expressions — and to manufacturing quality controls.
Color is critical to product labeling and an essential part of many quality control observations and processes. Color is a frequent specification for homeopathic raw materials and tinctures. It is also true that color can be a difficult characteristic to pin down. How can color be clearly specified if what you are working with is a material that will not fit in a colorimeter?
The U.S Food and Drug Administration (FDA) provides no specific guidance for the establishment of color specifications. The HPUS provides helpful but often vague color guidelines for tinctures and starting materials. Many companies have developed their own systems for identifying and referencing colors. One of the most effective is the use of the Pantone™ Formula Guide with more than 1,114 individual color shades. This color reference can simplify and standardize color identification and comparisons and be used to establish color specifications. While product labeling is an easy quality check with the use of a color chart to compare a printed label to the Pantone™ ink color, specifications for raw materials and tinctures can be trickier.
Metrics, Inc., a Greenville, North Carolina pharmaceutical developer, conducted a study on color identification for pharmaceuticals. They selected a group of scientists and asked them to identify a number of active pharmaceutical ingredient samples by color. The participants were provided with known quantities of the ingredients for comparison and asked to identify the samples by their color using visual appearance alone; they followed the standard pharmaceutical industry practice of viewing the material against a white background under laboratory lighting. Fewer than half of the participants identified the ingredients consistently.
The Metrics team then repeated the trial presenting samples to participants who examined them under diffused daylight, comparing them to Pantone™ color shades. Nearly 90% of participants correctly identified the materials based on color alone.
Setting quality specifications using the Pantone™ numbered color chip system can help to standardize color identification, whether for a specific color or a range of colors. Setting color standards for a given
material can be done by using several samples from different lots of the same material. Members of a panel examine the samples individually and select several color chips that best match the samples. The combined color chip selections are reviewed by the group and a final set of color chips selected as the standard to accommodate material variation.
Direct color comparisons can also reduce uncertainties and improve data collection helping to make quality personnel more confident in the process of color determination and when establishing specifications. It is well worth the investment for a Pantone™ color chip book. For best results keep your book out of the light in a dark place such as a drawer and for best results replace it annually or every two years as the color chips will fade.
Companies need to have a written Standard Operating Procedure (SOP) on how to perform the color comparisons that define the conditions under which the comparisons will be made; an area with consistent lighting not affected by external light sources works best. It is important to make certain that maintenance always replaces overhead lighting with the same bulbs (with the same Kelvin rating) for consistency. Employee training to the SOP can be done with a set of sample materials to be evaluated using the procedure; employee performance can tested with a different set of samples and a written test.
The procedure will need to be validated for reproducibility and accuracy with a larger group of individuals. One possibility is using a number of different sets of material samples, with some percentage of overlap to be evaluated over several days. This can function as both a measure of accuracy of identification and of reproducibility. The procedure and training must be monitored over time with retesting.
On a personal note; I have used Pantone™ books for color determination on everything from powdered, fresh, and dry herbs; standardized extracts to tinctures; and supplement capsules and tablets. I have had great reproducible results for over 20 years. Having several identified colors to compare a material to and being able to say yes it matches or no it does not is much better than having someone try to decide if it is yellow, yellowish green or greenish yellow or light green or spring green or … well some of the answers used to be terrible and not reproducible. And for labeling, Pantone™ books are ideal to maintain logo and label consistency. It works great and FDA inspectors thought they were sharp and a valuable addition to our QA program. Well worth the investment.
About the Author: Mary Beth Watkins served as Director of Product Development at Nutraceutical Corporation starting in 2007. Prior she was the Director of Scientific Affairs at Botanical Laboratories for 16 years. Her article originally appeared in the June 2011 hardcopy-only edition of the AAHP Network News. AAHP honored Ms. Watkins as an emeritus AAHP board member upon her retirement due to her years of dedicated volunteerism at the association.