drawOptions.coffee

drawControl.setDrawingOptions({
  polygon: {
    shapeOptions: {
      color: color
    }
  },
  marker: {
    options: {
      icon: L.mapbox.marker.icon({'marker-color': color}),
      draggable: true
    }
  }
})

Ah I see the issue. The object you pass into setDrawingOptions should be:

drawControl.setDrawingOptions({
  polygon: {
    shapeOptions: {
      color: color
    }
  },
  marker: {
    icon: L.mapbox.marker.icon({'marker-color': color}),
    draggable: true
  }
})

It works. Thanks.
But you should update the docs :)