Starting with the 2002 revision, the ANSI Z535.1 Standard for Safety Colors referenced inclusion of the closest Pantone® color number for each of the safety colors; which it provided within the separate but corresponding Z535 Color Chart. An example, that for safety red, is shown here. The intention of this inclusion was so that those requiring to know what (i.e.) safety red looks like, or those having no means to compare specific colors using instrument methods, could be provided a tangible and visual reference.
In reviewing customer specifications for safety signs and labels I have often observed that Z535’s inclusion of the closest Pantone® color match causes a certain amount of confusion for those needing to specify safety colors. This is a result of the spec writer’s inclusion of the Pantone® color into their own specification in a well intended effort to insure that their signs and labels utilize colors that conform to the Z535 standard. I have seen this inclusion practiced alongside the color name in a form such as (i.e.) “ANSI Safety Orange/PMS 152C”, or even as the Pantone® color reference used alone. This can present a problem for both the printer and the buyer of the print. The reason is that the actual Z535 color specifications are provided in terms of the Munsell Notation System; which is a three dimensional system that defines color in terms of hue, value, and chroma. But the specification is not a single point in three dimensional space, but rather it is a window or box within that space defined by +/- coordinate limits in each dimension. Again as examples, the coordinates for safety red and plots for all the safety colors, are shown here. So as opposed to there being a very specific color, the Z535 standard actually allows for a range of color that conforms to (i.e.) safety red.
Depending on print methods, consistent color control can be a challenge. And for a printer it can be very difficult to hit a specific, or ‘single point’ of color without some sort of defined tolerance. So the inclusion of a specific PMS color number in a customer’s specification without some sort of defined tolerance can leave the printer with a difficult, if not unobtainable task. And even if the variation for a specific safety color achieved by the printer conforms within the tolerance ‘window’ defined by the +/- three dimensional coordinate specifications in the Z535 Standard, the customers’ expectation is that the color be exactly (i.e.) PMS 152C. And if the color doesn’t provide an exact visual match to that PMS color, the customer believes it to be incorrect.
The Right Way to Specify Safety Color
So understanding that the closest matching Pantone® is provided in the z535 Standard only as a means of tangible visual reference, and that the actual specification is a set of coordinates that define a window of tolerance; it is only necessary to cite (i.e.) “ANSI Safety Orange” in your specifications. There is also no need to copy coordinate limits into your own specification. It is sufficient just to cite the ANSI Standard and let it do that work for you. But be sure you select a printer that specializes in printing safety signs and tags, knows and understands the z535 Standards, and has the color measurement tools and capability to reproduce the safety colors that conform to it.
Example images from ANSI Z535-2011 Safety Color Chart and ANSI Z535.1-2006 (R 2011) Safety Colors