UnityEngine.Gradient.SetKeys(UnityEngine.GradientColorKey[], UnityEngine.GradientAlphaKey[])

void Start()
    {

        LineRenderer lineRenderer = gameObject.AddComponent<LineRenderer>();
       // lineRenderer.material = new Material(Shader.Find("Particles/Additive"));
        lineRenderer.widthMultiplier = 0.2f;
        lineRenderer.numPositions = lengthOfLineRenderer;

        // A simple 2 color gradient with a fixed alpha of 1.0f.
        float alpha = 1.0f;
        Gradient gradient = new Gradient();
        gradient.SetKeys(
            new GradientColorKey[] { new GradientColorKey(c1, 0.0f), new GradientColorKey(c2, 1.0f) },
            new GradientAlphaKey[] { new GradientAlphaKey(alpha, 0.0f), new GradientAlphaKey(alpha, 1.0f) }
            );
        lineRenderer.colorGradient = gradient;
    }

public virtual Gradient GetNoodleGradient(XNode.NodePort output, XNode.NodePort input) {
            Gradient grad = new Gradient();

            // If dragging the noodle, draw solid, slightly transparent
            if (input == null) {
                Color a = GetTypeColor(output.ValueType);
                grad.SetKeys(
                    new GradientColorKey[] { new GradientColorKey(a, 0f) },
                    new GradientAlphaKey[] { new GradientAlphaKey(0.6f, 0f) }
                );
            }
            // If normal, draw gradient fading from one input color to the other
            else {
                Color a = GetTypeColor(output.ValueType);
                Color b = GetTypeColor(input.ValueType);
                // If any port is hovered, tint white
                if (window.hoveredPort == output || window.hoveredPort == input) {
                    a = Color.Lerp(a, Color.white, 0.8f);
                    b = Color.Lerp(b, Color.white, 0.8f);
                }
                grad.SetKeys(
                    new GradientColorKey[] { new GradientColorKey(a, 0f), new GradientColorKey(b, 1f) },
                    new GradientAlphaKey[] { new GradientAlphaKey(1f, 0f), new GradientAlphaKey(1f, 1f) }
                );
            }
            return grad;
        }