Who was the numbnut that thought an orange safety indicator was a good idea? What's to stop somebody from putting on orange indicator on a real gun?
Nothing.
But its rarely if ever done.
There isn’t much point in doing that.
The use case for a real gun very rarely would benefit from such a ruse.
A toy gun however can be made to look like a real one, if one wants to use it to threaten people, or even if one wants to make it look more impressive, if one’s friends are impressed by such things.