Digital Color Limitations
There are many different ways to communicate and view color. Color spaces are systems to communicate color through numeric values. Traditionally, all colors were communicated through physical color swatches or parts. But in the digital age, colors are increasingly communicated through digital values such as RGB or Hex values. (Note: RGB and Hex are exactly the same things, just in different numeric systems.)
Each different color space has its own method for describing color based on different assumptions and methodology (read more about color spaces). Mathematical formulas (including assumptions) exist to translate colors from one color space to another, which is why you often see the same color represented across a slew of different spaces such as RGB, Hex, CMYK, L*a*b*, HSL, HSV, and so on.
However, it is very important to understand the limitations of these numbers. While they are represented as very specific numbers, this specificity does not necessarily translate to an “exact color” because these numbers are device-dependent and do a poor job of accurately communicating color. Moreover, on-screen colors are just digital representations of color. They are not actual colors.
MyPerfectColor does its best to convert the digital color values to a physical color. We will make a color matching the color values you specify, but it is created and measured using our equipment and we cannot ensure it is the color you would be expecting.
Do not use digital color specifications if you are looking to accurately match an existing physical color, especially for touch up applications. The only way to accurately reproduce a physical color is by matching to a physical part. Read more about custom color matching services.
Why Digital Colors Are Problematic:
How were the color values generated in the first place? Digital color values are device-dependent. This means that the numbers generated are only comparable within the specific device. The values themselves do not communicate enough information to accurately reproduce a color across devices.
Measurements from different devices cannot be compared. For example, high-end spectrophotometers create a spectral curve by measuring the reflected light values of the visible light spectrum every 10 nanometers (over 30 measurements). A 45/0 spectrophotometer measures light reflected at 45-degrees whereas a spherical spectrophotometer measures light reflected at multiple angles. While each of these devices will provide a spectral curve and L*a*b* values, they are not comparable. They will measure the same color but output different values.
The little devices readily available for measuring colors such as the Nix and other scanners are colorimeters. They only measure 3 points in the spectral curve, and with much less accuracy. A phone uses software and camera technology to measure color and has far less accuracy. Oftentimes digital color values aren’t measured at all. They are generated on a computer by reading a photograph with a color picker app which can produce wildly inaccurate results. Or sometimes someone creates a purely digital/theoretical color using software. None of these different devices/methods produce measurements that are comparable across different devices. These are all very different methods that will yield very different results.
The display device will also produce varying results. Every different computer monitor, phone, tablet, or printer, will display the same color differently. A physical object is seen through reflected light bouncing off the surface and entering your eye. A digital color is generated by LED’s illuminating a color and shining it into your eye. A physical reflected-light color can never be as bright or vibrant as that of an illuminated color. Moreover, a physical color simply cannot be compared to an on-screen color. The human eye is not capable of comparing a reflected color to an illuminated color. Try holding an object up to your computer monitor and see how the colors compare. It is not possible to compare them. On-screen colors are there as a guide, but they are not precise, vary from screen to screen, and are not the actual colors.
Different color spaces are also designed for different things. RGB defines color by the amount of red green and blue it has, mimicking the red green, and blue cones in our eyes. This is most commonly used for computer display applications and doesn’t translate well into paint. In the RGB system, you can add the maximum red, green and blue and you get white. In paint, adding red, green and blue gives you brown. RGB is considered a device-dependent color space, which means the RGB value alone doesn’t communicate enough information about the actual color. The resulting color is affected by the equipment being used to generate and display it. Hex and RGB are identical. Hex represents the RGB colors using the hexadecimal numbering system. The first 2 digits of the Hex equals the R value, the second 2 digits represent the G value and the last 2 digits represent the B value.
CMYK is another device-dependent color space that is most commonly used for printing. The colors cyan, magenta, yellow, and black represent printing inks that combine with the white background of paper for creating colors. This color space also doesn’t translate well into paint since the white background cannot be used to brighten a color.
L*a*b* values, when generated using a spectrophotometer scanning the original color target, are less device dependent if they include the observer and light source (eg D65/2). But if you start with any other method and convert to L*a*b* values, then all the inherent limiting factors of the original measurement will be baked into the L*a*b* numbers and it will not be accurate.
The most reliable measure of a color would be a spectral curve created by a high-end spectrophotometer scan of the original target object, but even this has flaws because different devices and device geometries will produce different results.
MyPerfectColor offers a service to match digital color values, but given the inherent problems as discussed above, it will only make paint at the buyer’s own risk. MyPerfectColor recommends that colors are specified using color swatches or another physical method that provides both MyPerfectColor and the buyer a reliable way to communicate color so that MyPerfectColor can meet the buyer’s expectations. Given the limitations of digital color values, there is no way for MyPerfectColor to know the buyer’s expectations (eg what is the specific color the buyer has in mind? All paint is custom made to order and MyPerfectColor will not assume any risk when making paint based on digital color values. We are doing our best to communicate the issues so that the buyer will understand the risks and make an informed decision.