prop tip warning colors

Perhaps covered before, or considered trivial but...

Why did some countries use yellow or other colored prop tips for safety and others didn't?
Obviously the U.S. and U.K. and Japan did. But Germany and Italy, no. Russia, sometimes? France, sometimes? Others?
Were some countries more safety conscious than others? Why?
Any documentation?

just wondering...

Some German aircraft in WW2 had prop markings. One example was the Do 18: blue/yellow/red tip stripes (red was outermost). Perhaps the Do 18 had these markings because of the proximity of the crew when the aircraft was in the water.

Juanita

I thought it was very attractive that the prewar Grumman F3F had red, yellow, and blue prop tip warning stripes.

For civilian aircraft AC 43-13 specifies the nature and color options for prop tip warning strips. See AC 43.13-1B - Acceptable Methods, Techniques, and Practices - Aircraft Inspection and Repair [Large AC. This includes Change 1.] – Document Information I do not know how far back this requirement goes in terms of time period.