When creating a map from the plugin on the WP dashboard I can only select from the 500 or so markers in the library. How do I access the many more available in the widget, which I prefer not to use because I’m having issues with that too (separate support ticket!) or at least be able to change the colour of the standard red pin?
We have provided 500 markers which are maximum used by the users, you can also upload your custom markers as per your need. Please check this guide tutorial https://wpgmp.flippercode.com/docs/how-to-customize-the-marker-category-icons/ It really helps you.
This is not possible to change the color of default red marker, you can use any custom marker according to need.