I have yet more problems with gui and bullets Help please

I have a problem with my gui hud that I am using at the moment it looks ok but I need to fix a few things. The first is all of the bars on the screen are black and I need to figure out how to change the color of them and I need to know how to apply A texture to the ammo bar so it shows bullets instead of a bar. The problem with the bullet is when it enters my underwater trigger it activates the effect of the trigger and it gets very annnoying. I uploaded a video to show a visual rep : here I supplied annotations to point out where the problems where. The script for the GUIs is:

var pos : Vector2 = new Vector2(20,40);
var size: Vector2 = new Vector2(Screen.width / 2  ,20);
var progressBarEmpty : Texture2D;
var progressBarFull : Texture2D;
var barDisplay : float = 0;</p>

<p>function OnGUI()

<pre>`// draw the background:
GUI.BeginGroup (new Rect (pos.x, pos.y, size.x, size.y));
    GUI.Box (Rect (0,0, size.x, size.y),progressBarEmpty);

    // draw the filled-in part:
    GUI.BeginGroup (new Rect (0, 0, size.x * (exp / expneeded), size.y));
        GUI.Box (Rect (0,0, size.x, size.y),progressBarFull);
    GUI.EndGroup ();

GUI.EndGroup ();

} function Update(){ barDisplay = exp; ` This is the one from the exp script the big bar on the bottom it is incorperated within the exp script for the player I need to figure out how to change the color of this. the code for the underwater trigger is:

    //set your varibles here.
    var fog = false;
    var fogColor = Color (0, 0.4, 0.7, 0.6);
    var fogDensity = 0.04;
    var skybox : Material;
    //this is where you go underneath the water or in this case into the trigger aera
    //this is just the effect not anything to do with force.
    function OnTriggerEnter(other : Collider) {
        fog = true;
        RenderSettings.fog = fog;
        RenderSettings.fogColor = fogColor;
        RenderSettings.fogDensity = fogDensity;
        RenderSettings.skybox = skybox;
    //this is where we are exiting the water and the effect of being underneath the water is ended.
    function OnTriggerExit(){
        fog = false;
        RenderSettings.fog = fog;

I need to figure out how to get this to ignore my bullet gameObject / prefab any and all help is appreciated thank you

You want to change the color of the GUI?

Then I think this is of use to you.

Or this.

And this.

Please tell if this is not the solution.