For Coprinellus etc you can expect to see more blackish colour showing through the thin, translucent caps. When I look at the enlarged photo I see hints of white(ish) gills. Also, there are occasional hints of pinkish colour in some of the caps. That leads me to suspect that this is something in the Mycena clarkeana group, in which the fresh caps are pinkish to vinaceous – but become bleached with age. The caps in your photo show what look to be spots of mould, so I assume these mushrooms have been up for a while. I suspect that this cluster has grown from wood.