Color can be changed

Default color is red;
Color can be changed via config

NavBallDockingAlignmentIndicator.cs

@@ -6,19 +6,24 @@
 [KSPAddon(KSPAddon.Startup.Flight, false)]
 public class NavBallDockingAlignmentIndicator : MonoBehaviour
 {
-
+	
 	private NavBall navBall;
-
+	
 	private GameObject indicator;
 	PluginConfiguration cfg;
-
+	Color color;
+
 	void Start()
 	{
 		Debug.Log (" ======== AWAKE  ======== ");
 		this.cfg = KSP.IO.PluginConfiguration.CreateForType<NavBallDockingAlignmentIndicator>();
 		this.cfg.load();
-	}
+		Vector3 tmp = cfg.GetValue<Vector3>("alignmentmarkercolor", new Vector3(1f, 0f, 0f)); // default: red
+		this.color = new Color(tmp.x, tmp.y, tmp.z);
+		this.cfg.save ();
 
+	}
+
 	void LateUpdate()
 	{
 		if (this.navBall == null)
@@ -31,23 +36,23 @@ void LateUpdate()
 		    && FlightGlobals.fetch.VesselTarget != null 
 		    && FlightGlobals.fetch.VesselTarget.GetTargetingMode() == VesselTargetModes.DirectionVelocityAndOrientation) {
 			/// Targeted a Port if I am not mistaken o__o
-
+			
 			if (this.indicator == null)
 			{
 				SetupIndicator();
 			}
-
-
+			
+			
 			#region "legacy" Code
 			ITargetable targetPort = FlightGlobals.fetch.VesselTarget;
 			Transform targetTransform = targetPort.GetTransform();
 			Transform selfTransform = FlightGlobals.ActiveVessel.ReferenceTransform;
-
+			
 			// Position
 			Vector3 targetPortOutVector = targetTransform.forward.normalized;
 			Vector3 rotatedTargetPortInVector = navBall.attitudeGymbal * -targetPortOutVector;
 			this.indicator.transform.localPosition = rotatedTargetPortInVector * navBall.progradeVector.localPosition.magnitude;
-
+			
 			// Rotation
 			Vector3 v1 = Vector3.Cross(selfTransform.up, -targetTransform.up);
 			Vector3 v2 = Vector3.Cross(selfTransform.up, selfTransform.forward);
@@ -56,24 +61,25 @@ void LateUpdate()
 				ang = -ang;
 			this.indicator.transform.rotation = Quaternion.Euler(90 + ang, 90, 270);
 			#endregion
-
+			
 			// Set opacity
 			float value = Vector3.Dot(indicator.transform.localPosition.normalized, Vector3.forward);
 			value = Mathf.Clamp01(value);
 			this.indicator.GetComponent<MeshRenderer>().materials[0].SetFloat("_Opacity", value);
-
+			
 			this.indicator.SetActive(indicator.transform.localPosition.z > 0.0d);
 			return;
 		}
-
+		
 		if (this.indicator != null)
 			this.indicator.SetActive (false);
 	}
-
+	
 	void SetupIndicator()
 	{
 		this.indicator = GameObject.Instantiate(navBall.progradeVector.gameObject);
 		this.indicator.transform.parent = navBall.progradeVector.parent;
 		this.indicator.transform.position = navBall.progradeVector.position;
+		this.indicator.GetComponent<MeshRenderer>().materials[0].SetColor("_TintColor", this.color);
 	}
 }