#visualimpairment
As the tendency is quite clear, I tell you, what this symbol stands for (in Germany), before the poll will end:
It's not about this exact yellow color.
If you see a person wearing some kind of "bracelet" or a band around its upper arm, that shows a yellow circle that contains three black circles, it means that the person is visually impaired or blind.
There can be situations where this information getting upfront is helpful, for both the person showing its impairment as well as other persons interacting with them.
So, it seems that this symbol is quite unknow in large parts of the world.
As far as I know, the German Association for the Blind is in talks with the EU to spread information about its usage.