I got back to Sleeping Giant yesterday.  I was wrong - the trees are white.  It seems that part of the Nature Trail was discontinued, although the discontinued section still has some blazes.  You can see a bunch of my pictures of the blazes at https://photos.app.goo.gl/mhVc1hkw74GGw47W9 .  I thought the characters in the first field in the osmc:symbol were just a label for the tagger's convenience.  Have you gotten involved with Hiking.WaymarkedTrails.org?  I noticed the "stripe" option for the background recently became available.