The standard ANSI Z535.4, does not describe what the labels should actually look like nor the exact information that they should contain.
Z535.4 contains things, like the "formula" of the color red or orange so that the colors are consistent across industrial labels and signs. It also has definitions of the terms DANGER (something will happen) and WARNING (something might happen), but it does not contain any method for you to decide which word to use in your specific application. The standard also does not contain information on where or how labels and signs must be attached.
What is important from this standard is: the consistent use of colors and words (no red warnings or orange dangers); typeface size and symbols; and legal wording. A proper label should provide a statement (i.e. DANGER), a description of the issue (i.e. Hazard of Arc Flash or Electrical Shock), and how to avoid the issue (i.e. Do not open while energized). Most arc flash labels (the ones I think you are referring to as from 70E?) are more worried about saying what cloths to wear than they are about being proper ANSI Z535.4 labels. I know of no "computer" printer using toner or ribbons that can accurately reproduce the actual Z535.4 colors. In some peoples opinions, the NEC required label should be the colored "Warning/Danger do not do this" label and the 70E label should be an information only label (i.e. calories, HRC, voltage) without colors (per Z535.4).
