Color is one of the most important things in our lives. Colors affect us emotionally and psychologically, often to a degree that we are not even aware of. Therefore, the choice of colors plays a major role in launching new products, not least in the medtech field.
Color selection in medical device design always starts with the user …
When considering color, you need to understand who it is that will be using the product and what will appeal to them from a color standpoint. “Appeal” doesn’t mean what colors do they like. It means what are the characteristics and values the user will associate the product with. Does your (typical) user want the product to feel precise? Intelligent? Durable? Sophisticated? Are there particular colors/color combinations that they associate with those characteristics?
You can obtain knowledge of the user via a number of methods (a discussion of those methods is beyond the scope of this article). The point is that if you don’t know your user, you won’t be able to select product colors that will help the product sell and be well received in its market.
… and continues with the purpose
Once you understand your user, you can begin to devise a design strategy for developing a successful product – one that appeals to users and satisfies their wants. Beyond the medical function of the product, what are you trying to achieve with your design? Is your primary purpose to make the product easy to use? To make it appeal to a particular market segment? To give it an aura of precision, strength, etc.? To make it feel calming – or exciting – or fun? A good strategy will combine a number of elements that, when brought together, will achieve your goal. Color is one of the most powerful of those elements.
Work methodically with color selection
A process ensures thoroughness and consistency. To ensure that you consistently choose proper colors, your process should include an examination and analysis of these things:
- Existing (competing) products. What are others in the product space doing? Are their colors bold? Subdued? Should your product be consistent with the competition, or should it be markedly different? Are there certain colors that are expected?
- The environment in which your product will be used. Are there particular colors that dominate the environment? Is the environment visually busy, calm or in between? Will the product be used primarily in a hospital/clinic environment, in the home, or in public? How do you want your product to sit in that environment – should it stand out or should it blend in? Does it need to be discreet, or could it be a status symbol?
- Cultural considerations. Do you know what various colors symbolize in different cultures? How strong are those symbolic associations? Can they be ignored in favor of using color that will promote other design goals?
- Corporate colors. Many companies are tempted to use their corporate brand colors in their products. That can be appropriate if the brand colors fit with what the product needs to accomplish. Unless that is the case, the temptation to use corporate colors in the product’s color scheme should be avoided.
- Sterilization method. If your product is reusable, you need to consider how the sterilization method will affect the color of the product. EtO and gas plasma sterilization does not have a significant effect on color. Radiation sterilization using gamma or e-beam will cause a color shift toward yellow. Further information is available in this study by Eastman Plastics Color-shift will be most noticeable in transparent materials.
How to choose color for medical product design
Once you know what your users want and what your strategy will be for satisfying those user wants, what should the colors actually be?
Color Temperature
Start by choosing temperature. Most products will have one color that covers most of its surfaces. Should that dominant color be warm, cool or neutral? Look back at the color wheel. The green-cyan-blue side is cool, while the yellow-red-magenta side is warm. For the vast majority of medical products, you won’t want them to scream. So you’ll probably end up on the cool side. Indeed, most medical products currently and historically have used greens, blues and colors in the neutral space of whites/greys. There are several reasons for that. Most importantly, blues and greens are calming colors, which is what you want in the anxious environments of hospitals and clinics. There is a reason that medical robes most often have these colors.
David Pantalony authored an interesting article in the Canadian Medical Association Journal regarding how green became the color of hospitals and medical machines. He cites an American surgeon, Dr. Harry Sherman, as being the first to use green in the operating room in 1914. Finding the traditionally white environment to be too bright and glaring with new electric lighting systems, Sherman experimented with an operating room all in green, reasoning it was the color compliment to the red of hemoglobin. He found that his eyes could rest on anatomical features and details much better and without tiring. Around the same time, using color as a therapeutic treatment came into vogue, with green used for its calming qualities. Eventually, use of green in hospitals became pervasive.
What about the warm side of the color wheel?
Warm colors are great for accent colors, and for color coding purposes and for attracting attention. The contrast of color against a neutral background is easily perceived. Employing color contrast in a reasoned way will make the product easier to understand and to use.
Although warm colors will be used mostly for accent and effect, there are times when you might want to consider colors from the warm side of the wheel to be the dominant product color.
Warm colors are basically energetic and happy. Products designed for use in pediatric care is an area where you might want to use warm colors. Another area would be obstetrics/gynecology – associating pink as being feminine has a very strong bias in our culture. Purple also has a feminine association, though not as strong as pink. Similarly, medical products designed for ailments exclusive to the female anatomy could use warm colors as their dominant.
Finally, warm colors will promote a feeling of physical comfort – food, warmth and shelter (home). This suggests that warm colors could be considered for products used in recovery and patient rooms.
Neutral colors
By and large, the best choice for the bulk of a large medical product’s form is going to be one that serves as background onto which color and value contrasts can be selectively applied. White and light gray are good starting points. Pure white signifies cleanliness and purity – perfect for a medical product – but too much white can be overwhelming. When designing products for use in the operating suite and other environments having areas of high illumination, be especially sensitive to the fact that white reflects the most light, causing glare and tiring the eyes. Giving the product’s white surfaces a matte finish will mitigate those problems somewhat.
Limiting your palette to white and light gray is just that – limiting. Subtle additions of hue can provide a significant shift in how the color feels, while still keeping the surfaces predominantly neutral.
A functional reason for employing white, light gray or subtle tints is because unclean areas will contrast against the light background, making it easier to see whether the product has been cleaned thoroughly.
Siemens Acuson X700. Photo: Siemens.
A reason for employing darker colors would be if the product is reusable and will be sterilized using gamma or e-beam radiation. As mentioned above, those methods shift colors toward yellow (to a varying extent, depending on the material). Any yellow shift will be less noticeable in dark colors. Dark colors also conceal dirt – a good reason for using dark colors on casters and around the base of floor-standing products.
In the ultrasound cart in the image, the use of dark gray implies serious, no-nonsense. “I’m here to do a job”. The dark gray also provides a contrast to the light gray, thereby drawing your attention (a cue that makes for good usability) to the handle (which also attracts attention because it’s the only form that’s set at an angle). Dark gray is also used at the control surface – the area of the machine that will be touched the most and therefore will have a tendency to get dirty. The dark (low) value of the grey will hide smudges.
Light gray is the dominant color. It also says, “don’t pay attention to me – I’m in the background”. The relatively high value of that gray makes the cart feel visually lighter. If the gray were darker, such a large machine would feel ponderous. If the dominant color was white instead of gray, the cart would also take on a different character. It would feel “purer” (which isn’t necessarily needed in this context), “happier” and would attract more attention to itself, detracting from its seriousness. The monochromatic appearance furthers the effect of solid, business-like seriousness. The few areas of pastel accent color add an element that mitigates the austerity of gray and helps make the machine feel approachable and not intimidating.
A technical note on color
There are many different models for describing and specifying color. This article was written mostly from the perspective of the Hue-Saturation-Value model (HSV).
Editor’s comment: HSV is the color system most commonly used in various computer programs to mix colors, such as in Photoshop. To reproduce a color, HSV is often preferred to RGB or CMYK because the system resembles human color.
When most people think of a “color”, what they’re thinking of is its hue – red, green, blue, yellow, etc. Hue is just one dimension of a color, however. Colors also have different levels of saturation and different levels of value.[/highlight]Color is just as important in medical products as it is in other areas of our lives. The delivery of health care is evolving to take into account the entire patient experience to a much greater extent than it has in the past. According to David Scott of KYDEX LLC , “As healthcare facilities are being designed or redesigned to create patient-centered environments, we’re seeing more attention focused on the external design of medical devices. In these cases, the machines are just as critical to the overall perception of the room and the healthcare experience as the color of the walls and choice of furnishings.”
Response to color varies between successive time periods (trends/fashion) and between cultures. Colors and color combinations also take on connotations due to the way they are used commercially (branding) and how prevalent they become in that context. Colors and color palettes also cycle in popularity. Indeed there is an entire industry based around predicting color trends (e.g. check Pantone’s color of the year).
For the reasons noted above, choosing color is a moving target. Which explains why there is no definitive method for making color choices. So how can a developer of medical products bring some rationality to an endeavor that will remain subjective? The goal of this article is to provide a conceptual framework that those in medical product design and development can use to make effective color choices.
This is a shortened version of the article Choosing Medical Product Colors authored by Dan Stipe, Sr Director of Industrial Design at Forma Medical Device Design in North Carolina, USA.
