Clip for change button color when scroll

Question

I am trying do it: CSS change color on scroll / cut text - overflow z-index It is use clip for change color of a button when somebody are scrolling. I want it changes when move from header to body, but it doesn't work for me.

body { 
	background:#F7FE2E;
	margin: 0;
}

#header{ 
	padding:200px 50px;
	background-color: #6495ED;
}

/*HERE IS THE HEADER AND BODY CLIP*/
#header, 
#content {
	clip: rect(auto, auto, auto, auto);
	box-sizing: border-box;
}

/********** MENU ***********/

.menu{
	top: 15px;
	right: 40px;
	font-size: 16px;
	position:fixed;
}

.black {
   color: #000000;
}

.white {
   color: #FFFFFF;
}

	<div id="wrapper">

	  	<div id="header">

			<!--HERE IS THE FIXED MENU WHITE-->
	   		<div class="menu white">MENU</div>

		</div>

		<div id="content"> 

	    	<!--HERE IS THE FIXED MENU BLACK-->
	    	<div class="menu black">MENU</div>

	    	CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>CONTENT<br>

	    </div>

	</div>		 

Why it doesn't work?

Answer 1

Here's the answer you needed, you just missed a few rules. Check the snippet below for comments...

body {
  background: some-arbitrary-color; /* clipping doesn't use THIS color => */
  margin: 0;
}
#header {
  top: 0; /* [OPTIONAL] add */
  padding: 200px 50px;
  background-color: #6495ED;
}


/* [MANDATORY] add */
#content {
  top: 400px;                /* (2 x 200px) px, vw, %, whatever works best*/
  background-color: #F7FE2E; /* => but NEEDS this bg-color to mix */
}
/*******************/


/*HERE IS THE HEADER AND BODY CLIP*/
#header,
#content {
  position: absolute; /* [MANDATORY] add, clipping needs absolute positioning */
  width: 100%;        /* [MANDATORY] add, and position needs width */
  clip: rect(auto, auto, auto, auto);
  box-sizing: border-box;
}
/********** MENU ***********/
.menu {
  top: 15px;
  right: 40px;
  font-size: 16px;
  position: fixed;
}
.black {
  color: #000000;
}
.white {
  color: #FFFFFF;
}

<div id="header">

  <!--HERE IS THE FIXED MENU WHITE-->
  <div class="menu white">MENU</div>

</div>

<div id="content">

  <!--HERE IS THE FIXED MENU BLACK-->
  <div class="menu black">MENU</div>

  CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
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  <br>CONTENT
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  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
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  <br>CONTENT
  <br>CONTENT
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  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>CONTENT
  <br>

</div>

</div>