Many safety labels use either Caution, Warning or Danger with a specific color associated with it.
The U.S. National Electrical Code and NFPA 70E both reference ANSI Z535 to provide guidance regarding effective words, colors and symbols for signs and labels that provide warning about electrical hazards.
Other countries may have a different standard for guidance.
Here is this week’s question:
How familiar are you with the ANSI Z535 Series of Standards for Safety Signs and Tags
Not in the U.S. / Doesn’t apply
Know about it
I’ve read it