underwater fog script

i cant figure out why no matter what i do it wont come out as the color blue, aqua, or even clear. it always comes out a yellowish

 //set your varibles here.
    var fog = false;
    var fogColor = Color (0, 0, 1, 1);
    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;
    }