Accessing C# scripts from other objects

I’m sure this is asked a lot, but I have looked around but nothing seems to help fix this. I have a script that is going to activate image effects on a camera when the camera goes below a certain y value. I have linked the camera GameObject through the script and that seems to work fine, however, when I tried to link the three image effects, I get errors for each one stating that “The type or namespace name could not be found”

Here is the script:

using UnityEngine;
using System.Collections;

public class WaterEffect : MonoBehaviour {

	GameObject WaterTop;
	GameObject WaterBot;

	bool UnderWater;
	
	GameObject PlayerCamera;

	private Blur BlurEffect;
	private ColorCorrectionCurves ColCorEffect;
	private GlobalFog GloFogEffect;

	// Use this for initialization
	void Start () 
	{
		PlayerCamera = GameObject.Find("FirstPersonCharacter");
		BlurEffect = PlayerCamera.GetComponent<Blur>();
		ColCorEffect = PlayerCamera.GetComponent<ColorCorrectionCurves>();
		GloFogEffect = PlayerCamera.GetComponent<GlobalFog>();
	}
	
	// Update is called once per frame
	void Update () 
	{
		if(PlayerCamera.transform.position.y < gameObject.transform.position.y){
			UnderWater = true;
			BlurEffect.active = true;
			ColCorEffect.active = true;
			GloFogEffect.active = true;
		} else if(PlayerCamera.transform.position.y > gameObject.transform.position.y){
			UnderWater = false;
			BlurEffect.active = false;
			ColCorEffect.active = false;
			GloFogEffect.active = false;
		}
	}
}

You’re missing the namespace for the effects. Edit the very top of your script with this:

using UnityEngine;
using System.Collections;
using UnityStandardAssets.ImageEffects;