Pink circles on progression chart

What do these represent? I’ve read articles on the blog and FAQs, but can’t seem to find the explanation. The meaning of the gold, silver and bronze circles is explained in the blog- but I couldn’t find an explanation for the pink circles. Perhaps I just haven’t looked hard enough? Would be grateful for an explanation of what these mean.

Cheers,

These activities are those where you came close but didn’t quite get a breakthrough.