Campgrounds and potential new POI color

[wmisener]

Campgrounds have a long tradition of being prominently displayed on American road maps, so they are very appropriate for this project. I think the icon to use is fairly obviously some sort of tent. I personally quite like the NPS icon:

Campgrounds (OMT class=campsite + subclass=camp_site) appear in the tiles beginning at z14, so that puts a practical limit on how early we can render them, despite American road maps sometimes displaying camping POIs even at state-wide scales.

What I'm most interested to discuss is what color to make the icon. The contributing guidelines have long left a spot open for an "outdoors" POI color, presumably a shade of green. This category could be appropriate for campsites, as well as other POIs like sports fields, picnic sites, and maybe even natural features like peaks (though that might be worth a separate discussion). If we go with green, care will be needed to choose a shade that contrasts appropriately with the park background fill many campgrounds will be on top of. Relatedly, would it be acceptable for the POI label text to be a similar shade of green as the park labels, or do they need to contrast? We'll also want to consider accessibility for color-blind users (see #1038), whether that means choosing a shade that transforms to a sufficiently different color under color-blindness or implementing some kind of color switcher.

Alternatively, campsites could plausibly be grouped with hotels in consumer-orange, or as attraction-brown.

Distinguishing campgrounds from individual campsites could be a candidate for a treatment similar to how we distinguish bus stops vs. stations: by inscribing the campground in a circle. But this is getting ahead of things, since tourism=camp_pitch is not present in the OMT tiles as far as I can tell.

[adamfranco]

I like the idea of distinguishing camp_pitch via lack of circle.