black line renderer

Hello everyone! I've got a problem with my 2d game. My line renderer is always black (it should be kind of light brown). I searched up on google and I think it might be a problem with its lightning, but I didn't manage to solve the problem. Can somebody help? I don't exactly know what else should I mention beside the photos, but if you want to, please ask me! Thank you!

function DrawGrapple() is called in Update()

 public LineRenderer lr;
 private Vector2 grapplePoint;

 private void DrawGrapple()
 {
     lr.enabled = grappler.enabled;
     if (!lr.enabled)
         return;
     lr.SetPosition(0, new Vector3(transform.position.x, transform.position.y + 0.5f, 0.1f));
     lr.SetPosition(1, new Vector3(grapplePoint.x, grapplePoint.y, 0.1f));
 }