Problems with changing the colour of text through script

Hey guys,
So what I want to do is once a user collects an item a number will appear in the middle of the screen then fade away.

Green text - When an item is picked up.
Red text - When an item is dropped.

What I have so far:

Code (CSharp):

1.     public Text bookweightA;
2.     public Text bookweightS;
3.  
4.     public Text mapweightA;
5.     public Text mapweightS;
6.  
7.     Color visibleG = new Color(124f, 255f, 130f, 100f);
8.     Color visibleR = new Color(255f, 124f, 124f, 100f);
9.  
10. void OnTriggerStay(Collider other)
11.     {
12. ...
13. bookweightA.color = visibleG;

Now the problem I'm having is that the text is not changing colour, it just appears white, however the alpha values works!

 

I believe color values are from 0.0 to 1.0

 

I tried something different instead and got the desired color, how would I fade it back out?
This is my attempt thus far?

Code (CSharp):

1.             Color c = bookweightA.color;
2.             c.a = 100;
3.             bookweightA.color = c;
4.             timeleft -= Time.deltaTime;
5.             if (timeleft == 0)
6.             {
7.                 c.a = 0;
8.                 bookweightA.color = c;
9.             }

 

This is the output of my debug.log of the timeleft variable everytime I pick up and drop the object.

Anybody know why?

I declared timeleft at the top of the script:

Code (CSharp):

1. float timeleft = 2.0f;

 

So I picked up and dropped my object up roughly 200 times and as the timer become equal to or less than 0 my text disappeared as desired, so there is a problem with my timer pausing? Anyone know how I can fix it?


EDIT: Is utilising a timer the best way about going this, is there a way I can do something like...
Wait 2 seconds
Change alpha of the text back to 0.?

 

I suggest you take a look at coroutines. :')

 

How would I go about doing?
Is it best to utilise co-routines for this problem or just a simple timer?

 

Have you tried using CrossFadeColor() ?

http://docs.unity3d.com/460/Documentation/ScriptReference/UI.Graphic.CrossFadeColor.html

 

Thanks Fajl, this has helped me get a step further towards my solution.
I used CrossFadeAlpha() instead, it works perfectly as I wanted the first time I pick up the item.
The text component appears "+1.2kg" then fades after 2secs, however if I drop the item and try pick it up again it does not work

Code (CSharp):

1.         if (other.gameObject.tag == "book" && Input.GetKey("e"))
2.         {
3.             itemweight = 1.2f;
4.             ScoreManager.currentweight += itemweight;
5.             other.gameObject.SetActive(false);
6.             bookimage.color = visible;
7.             isholding = true;
8.             Color c = bookweightA.color;
9.             c.a = 100;
10.             bookweightA.color = c;
11.             bookweightA.CrossFadeAlpha(0, 2, false);

Full script (if needed):

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.UI;
3. using System.Collections;
4.  
5. public class ObjectPickup : MonoBehaviour
6. {
7.     public Image bookimage;
8.     public Image mapimage;
9.  
10.     public Text bookweightA;
11.     public Text bookweightS;
12.  
13.     public Text mapweightA;
14.     public Text mapweightS;
15.  
16.     public static float itemweight;
17.  
18.     bool isholding;
19.     //float timeleft = 2;
20.     Color visible = new Color(0f, 0f, 0f, 100f);
21.     Color invisible = new Color(0f, 0f, 0f, 0f);
22.  
23.     GameObject book;
24.     GameObject map;
25.  
26.     void Start()
27.     {
28.         book = GameObject.FindGameObjectWithTag("book");
29.         map = GameObject.FindGameObjectWithTag("map");
30.         //anim = GetComponent<Animator>();
31.     }
32.  
33.  
34.     void Update()
35.     {
36.         if (Input.GetKey("q") && isholding == true)
37.         {
38.             DropItem();
39.         }
40.     }
41.  
42.  
43.     void OnTriggerStay(Collider other)
44.     {
45.         // If the entering collider is a book...
46.         if (other.gameObject.tag == "book" && Input.GetKey("e"))
47.         {
48.             itemweight = 1.2f;
49.             ScoreManager.currentweight += itemweight;
50.             other.gameObject.SetActive(false);
51.             bookimage.color = visible;
52.             isholding = true;
53.             Color c = bookweightA.color;
54.             c.a = 100;
55.             bookweightA.color = c;
56.             bookweightA.CrossFadeAlpha(0, 2, false);
57.             /*timeleft -= Time.deltaTime;
58.             Debug.Log(timeleft);
59.             if (timeleft <= 0)
60.             {
61.                 c.a = 0;
62.                 bookweightA.color = c;
63.                 timeleft = 0;
64.             }*/
65.         }
66.         // If the entering collider is a map...
67.         else if (other.gameObject.tag == "map" && Input.GetKey("e"))
68.         {
69.             itemweight = .2f;
70.             ScoreManager.currentweight += itemweight;
71.             other.gameObject.SetActive(false);
72.             mapimage.color = visible;
73.             isholding = true;
74.             Color c = mapweightA.color;
75.             c.a = 100;
76.             mapweightA.color = c;
77.         }
78.         else
79.         {
80.         }
81.     }
82.  
83.        
84.     void DropItem()
85.     {
86.         if (bookimage.color == visible)
87.         {
88.             itemweight = 1.2f;
89.             ScoreManager.currentweight -= itemweight;
90.             bookimage.color = invisible;
91.             Vector3 position = GameObject.Find("CollectableSpawnPoint").transform.position;
92.             GameObject item = Instantiate(book, position, Quaternion.identity) as GameObject;
93.             item.gameObject.tag = "book";
94.             item.gameObject.SetActive(true);
95.         }
96.         if (mapimage.color == visible)
97.         {
98.             itemweight = .2f;
99.             ScoreManager.currentweight -= itemweight;
100.             mapimage.color = invisible;
101.             Vector3 position = GameObject.Find("CollectableSpawnPoint").transform.position;
102.             GameObject item = Instantiate(map, position, Quaternion.identity) as GameObject;
103.             item.gameObject.tag = "map";
104.             item.gameObject.SetActive(true);
105.         }
106.         isholding = false;
107.     }
108. }

 

I'm still unsure why CrossFadeAlpha() isn't working after dropping the item once