CoroutineExample.cs

using UnityEngine;

public class CoroutineExample : MonoBehaviour {

	void Start () {
		StartCoroutine("YourCoroutine");
	}

	IEnumerator YourCoroutine() {
		// do something immediately
		SpriteRenderer spriteRenderer = GetComponent<SpriteRenderer>();
		spriteRenderer.color = Color.red;

		// do something after 5 seconds
		yield return new WaitForSeconds(5f);
		spriteRenderer.color = Color.red;

		// do something over the next 3 seconds
		for (float t = 0; t < 3f; t += Time.deltaTime) {
			float fraction = t / 3f;
			spriteRenderer.color = Color.Lerp(Color.red, Color.blue, fraction);
			yield return new WaitForEndOfFrame(); //infinite loop if this line is missing
		}
		
		// wait for some other coroutine to finish
		yield return StartCoroutine("SomeOtherCoroutine");
		spriteRenderer.color = Color.black;
		
		// run coroutine in parallel(ish)
		StartCoroutine("SomeOtherCoroutine");
		spriteRenderer.color = Color.white;
	}
	
	IEnumerator SomeOtherCoroutine() {
		// does nothing but yield return is required when the return type is IEnumerator
		yield return null;
	}
}