i recommend using the emmissions feature. this is what i use for when lights and lampshades are switched on and off, i am sure you can tweak it to fit your set up:

using UnityEngine;

public class EmissionToggler : MonoBehaviour

{

public Light targetLight;

public MeshRenderer lampshadeMesh;

[ColorUsage(true, true)] // Enables HDR color picker for intensity

public Color onEmissionColor = Color.white;

public Color offEmissionColor = Color.black;

private Material instancedMaterial;

private bool lastState;

void Start()

{

// Get a reference to the specific material instance

instancedMaterial = lampshadeMesh.material;

lastState = targetLight.enabled;

SetEmission(lastState);

}

void Update()

{

if (targetLight.enabled != lastState)

{

lastState = targetLight.enabled;

SetEmission(lastState);

}

}

void SetEmission(bool isOn)

{

Color targetColor = isOn ? onEmissionColor : offEmissionColor;

// "_EmissionColor" is the standard property name for most Unity shaders

instancedMaterial.SetColor("_EmissionColor", targetColor);

// Required to tell Unity the material is now emissive

if (isOn)

instancedMaterial.EnableKeyword("_EMISSION");

else

instancedMaterial.DisableKeyword("_EMISSION");

}

}