The following script is an example of how in Unity to countdown a number to zero while fading the text color from green to red.

I use this script and method in my Unity game Binary Blitz to countdown a bonus value as time runs out.

Here is how it looks.

Unity c# color countdown

Using the script

  • Create a new “Bonus” C# Script in your project and past in the below script
  • Add some UI Text to your scene.
  • Drag your script to the Text in the inspector
  • Change the public variables to fit your needs

The Script

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class Bonus : MonoBehaviour {

    public float updateBonusEvery = 0.05f; // seconds
    public int MAX_BONUS = 10000;
    public int STEP = 30;

    private float timeTillBonusUpdate;
    public int bonusRemaining;

    // Use this for initialization
    void Start () {
        ResetBonus();
    }
	
	// Update is called once per frame
	void Update () {
        if (GameController.instance.isPaused == false)
        {
            //Update Bonus
            var bonusTimer = Time.deltaTime;

            timeTillBonusUpdate -= bonusTimer;

            if (timeTillBonusUpdate <= 0)
            {
                timeTillBonusUpdate = updateBonusEvery;
                updateBonus();
            }
        }
    }

    private void updateBonus()
    {
        if (bonusRemaining >= STEP)
        {
            // Reduce the remaining bnus
            bonusRemaining -= STEP;

            // Bonus Font Color
            float H = 0.35f / ((float)MAX_BONUS / (float)bonusRemaining);
            float S = 1f; // Saturation
            float B = 0.75f; // Brightness

            Color bonusColor = Color.HSVToRGB(H, S, B); //Font Colour

            // Change Text and Colours
            this.gameObject.GetComponent<Text>().color = bonusColor;
            this.gameObject.GetComponent<Text>().text = "Bonus: " + bonusRemaining.ToString();
        }
        else
        {
            // We are zero 
            float H = 0f;
            float S = 1f; // Saturation
            float B = 0.75f; // Brightness

            bonusRemaining = 0;
            Color bonusColor = Color.HSVToRGB(H, S, B);
            this.gameObject.GetComponent<Text>().color = bonusColor;
            this.gameObject.GetComponent<Text>().text = "Bonus: 0";
        }

    }

     public void ResetBonus()
     {
        bonusRemaining = MAX_BONUS;
        timeTillBonusUpdate = updateBonusEvery;
     }

}