How to draw lines of the desired color?

Question

Game development

Hello!
Figured out how to draw lines on the playing field.
I do it like this:

private void DrawLine(Vector3 start,  Vector3 stop, GameObject template)
    {
        GameObject toInstiateGridLine = template;
        GameObject gridLineInstance = Instantiate(toInstiateGridLine, start, Quaternion.identity) as GameObject;
        LineRenderer gridLineRenderer = gridLineInstance.GetComponent<LineRenderer>();
        gridLineRenderer.SetVertexCount(2);
        gridLineRenderer.SetWidth(0.01f, 0.01f);
        gridLineRenderer.SetColors(Color.black, Color.black);
        gridLineRenderer.SetPosition(0, start);
        gridLineRenderer.SetPosition(1, stop);
    }

Lines are drawn but pink (I'm expecting black). It looks like this:

Here are the settings of the LineRenderer component created at runtime:

Actually the question. How to make lines black?
Question on SOF.

Answer 1

The problem was that the LineRenderer didn't have a material.
I solved it with one line:
When accessing the material property, if it does not exist, a default material is created.
It is also possible to create the material yourself and attach it to the component (see SOF answer).