I wouldn't say "many." It's certainly possible to have a dunkelgrau flak gun that survived until the end of the war, but I'd say that the
vast majority of them would've been dunkelgelb by that point. Considering the directive went out in February of 1943, there's a much higher chance that a flak gun in '45 would've been created after that time.
It's also hard to judge B&W images when it comes to color. Lighting, contrast etc... can all effect how they look. The one that you posted in front of the Reichstag looks dark;
while other photos look light;
It's also good to keep the 88 the same color as the pak40s etc... that are being used.
If the map is about a specific unit in Berlin, or a specific sector where there's evidence of dunkelgrau being used, then that would justify going against the status quo. But in general, dunkelgelb would've been much more common.