how would i fix the compiler errors

 using System;
 using UnityEngine;
 using UnityStandardAssets.ImageEffects;
 
 
 [ExecuteInEditMode]
 public class ColorGradingProperties : ObjectProperties {
     private Tonemapping toneMapping;
     //public Light _moon;
     public Gradient exposure;
     //public Gradient exposure, brightness,contrast,saturation;
     public Vector2 exposure2 = new Vector2(1, 2), brightness2 = new Vector2(1, 1), contrast2 = new Vector2(1, 1.1f), saturation2 = new Vector2(0, 1);
     public float crossFade;
 
 
     public new void Awake() {
         toneMapping = GetComponent<Tonemapping>();
         base.Awake();
     }
 
     public override void Run() {
         if (!enabled) return;
         UpdateTone(time);
     }
 
 
     public void Update() {}
 
     //public new void OnEnable() {
     //    if(debugLogness)Debug.Log("ColorGrading OnEnable");
     //    UpdateTone(time);
     //    base.OnEnable();
     //}
 
     private void UpdateTone(float timeIn) {
         if (debugLogness) Debug.Log("ColorGrading UpdateTone: time:" + timeIn + " crossFade:" + crossFade + " :" + toneMapping, this);
         if (toneMapping == null) toneMapping = GetComponent<Tonemapping>();
         var crossTo = 0f;
         var crossFade2 = crossFade;
         if (crossFade < 0) {
             crossTo = 30;
             crossFade2 = -crossFade;
         }
         if (exposure != null) toneMapping.exposureAdjustment = Mathf.Lerp(Mathf.Lerp(exposure2.x, exposure2.y, exposure.Evaluate(timeIn).r), crossTo, crossFade2);
         if (exposure != null) toneMapping.Brightness = Mathf.Lerp(brightness2.x, brightness2.y, exposure.Evaluate(timeIn).r);
         //if (exposure != null) toneMapping.Brightness = Mathf.Lerp(Mathf.Lerp(brightness2.x, brightness2.y, exposure.Evaluate(timeIn).r), Mathf.Lerp(brightness2.x, brightness2.y, exposure.Evaluate(timeIn).r)*0.0f, Mathf.Max(0, crossFade*2f - 0.5f));
 
         if (exposure != null) toneMapping.Contrast = Mathf.Lerp(Mathf.Lerp(contrast2.x, contrast2.y, exposure.Evaluate(timeIn).r), 1f, crossFade);
         if (exposure != null) toneMapping.Saturation = Mathf.Lerp(saturation2.x, saturation2.y, exposure.Evaluate(timeIn).r);
     }
 }

this is what was there and i attempted to fix it but after i did it continued to say there were errors these were the errors Assets/Scripts/Properties/ColorGradingProperties.cs(45,51): error CS1061: Type UnityStandardAssets.ImageEffects.Tonemapping' does not contain a definition for Brightness' and no extension method Brightness' of type UnityStandardAssets.ImageEffects.Tonemapping' could be found (are you missing a using directive or an assembly reference?)

Assets/Scripts/Properties/ColorGradingProperties.cs(48,51): error CS1061: Type UnityStandardAssets.ImageEffects.Tonemapping' does not contain a definition for Contrast' and no extension method Contrast' of type UnityStandardAssets.ImageEffects.Tonemapping' could be found (are you missing a using directive or an assembly reference?)

Assets/Scripts/Properties/ColorGradingProperties.cs(49,51): error CS1061: Type UnityStandardAssets.ImageEffects.Tonemapping' does not contain a definition for Saturation' and no extension method Saturation' of type UnityStandardAssets.ImageEffects.Tonemapping' could be found (are you missing a using directive or an assembly reference?