How to change a color of a GUI Button on click

how do i change the color of GUI Button when clicked on thst particular button.
can anyone help with C# code…

Thanks for your answer in Advance

Ok I removed the old answer since I realized I was going nowhere. Now this one is tried and working:

bool blue;
void Start(){
  blue =true;}
    
void OnGUI() {   
    if(blue)
      GUI.color = Color.blue;
    else
      GUI.color = Color.yellow;
    if(GUI.Button(new Rect(100,110,70,30), "A button"))   
        blue= !blue;
}

I did it with Js and translate it to c# here so you might want to check twice the syntax as I am not using c# and am not confident with it…

original Js version

var blue:boolean = true;

function OnGUI() {
    if(blue)
    	GUI.color = Color.blue;
    else
     	GUI.color = Color.yellow;
    if(GUI.Button(Rect(100,110,70,30), "A button"))      
        blue= !blue;       
}

You have to assign a GUIStyle to the button and replace the background image.

var gStyle : GUIStyle;
var blueTex : Texture;
var redTex : Texture;


function Start() {
    gStyle.normal.background = blueTex
}

function OnGUI() {
    if(GUI.Button(Rect(0, 0, 100, 100), "Change Color" gStyle))
        gStyle.normal.background = redTex
}