How to manually set a color of a LineSeries via json config in amcharts v4?

I've tried lots of properties and it had no effect:

    ...
    "series": [
        {
            "type": "LineSeries",
            "propertyFields": {
                "stroke": "#color",
                "fill":   "#color"
            }
        },
        {
            "type": "LineSeries",
            "color": "#color"
        },
        {
            "type": "LineSeries",
            "fill": "#color"
        },
        {
            "type": "LineSeries",
            "sprite": {
                "color": "#color"
            }
        },
        {
            "type": "LineSeries",
            "sprite": {
                "fill": "#color"
            }
        },
        {
            "type": "LineSeries",
            "stroke": {
                "color": "#color"
            }
        },
        {
            "type": "LineSeries",
            "stroke": {
                "fill": "#color"
            }
        }
    ]

Does amcharts v4 have a simple and easy way to manually set a color of a line?

Solution

You almost had it. You have to set the stroke at the top-level of the LineSeries definition (see JSON tab in the docs):

"series": [{
  "type": "LineSeries",
  "stroke": "#567890",
  // ...
},
// ...
]

JSON values line up very closely to the declarative syntax, hierarchy-wise. You can find more full JSON examples in the github repo.