The smaller arrow should be red. The direction of the larger, black arrow shows the traffic that has priority on the narrow street. And they are driving on the left.
Monochrome can be dangerous sometimes!
In this case the sign seems to read vertically, which makes a whole different story.
Thanks for your comments mshchem and Graham. Yes the black arrow has priority on a narrow street. Because the sign seems to read vertically perhaps it's a bit more ambiguous? I too love signs.