color Tint camera

I'm trying to make a swimming script and am somewhat successful, but what i need now is, when the main camera is under water i would like to tint the whole screen a blue-ish color to simulate the underwater feeling. How would i go about doing this?

If you have a Pro license(or using the 30day free trial) you have access to image post processing effects. You can check out the effect in this project or just have a look at it via the webplayer here.

Otherwise you could use a cheap trick maybe by making a plane the child of the camera facing it and assign a material to it that makes it transparent and essentially you will see "everything" through this plane. The results are not that nice but it might be good enough for you.

Also check out the Render Settings page and see if a colored fog is applicable for your project.

Use this shader on a triangle or quad that takes up the whole screen. Due to ZTest Always, you don't even need to worry about how far away from the camera it is, or if other things are in front of it. (The alpha channel of the color controls how opaque it is.)

Shader "Transparent Color" {

Properties {
    _Color ("Color", Color) = (1,1,1,.5)
}

SubShader {
    Tags {Queue = Overlay}
    ZTest Always
    Blend SrcAlpha OneMinusSrcAlpha
    Color [_Color]
    Pass {}
} 

}

I'm really noobish, so I can't say I have a lot of experience, but I very recently was trying to do something similar in one of my games. What I did was make a GUI Texture in Unity and make it the size of the entire screen, in your case you would make it a blue-ish color, and then you could change the alpha value of the texture's color to make the texture mostly see-through. It's crude, but it worked really well for my project

Create a fullscreen panel and give a color you want to it.

Search before you ask link.