Thanks for the kind words about the plugin, Davis 🙂
Just to be clear, when you describe the “map marker”, do you mean the fairly narrow marker that appears above an event “inside” (or, on top of) the Google Map itself? Here’s a screenshot of one of these markers, for reference:

I just want to be 100% certain about what you’re talking about, because if this marker is what you’re talking about, then I hate to bear the bad news but it’s unfortunately a tricky thing to customize 🙁 That’s because it’s mostly generated by the Google Maps API itself – in other words, unlike almost everything else on our views, there’s not a Tribe template file that defines how that looks.
Let me know if this is the marker you mean and we can go from there – we’re very limited with options here for those Google Maps API markers, but I can recommend some things for sure.
Thanks,
George