JavaScript Session storage variable on another page

So I'm rather new to JavaScript and I would love some help getting this code to work. I've looked at multiple other posts talking about session storage as well as if/else statements and still can't seem to figure it out.

I have a page, lets call it page 1 and it has 3 links, "red" "green" and "blue".

When you click on any of these links its function sets a session storage variable 'colorVar' to the color chosen and then redirects to a page called page 2.

As page 2 loads, the window.onload action is used to start a function according to the variable set on page 1. In this case the function that starts on page 2 simply displays "Your color is ____!".

Heres the code:

<!-- [This is Page 1] -->

<a href="Page2.html" onclick="colorRed()">Set color to red</a>
<a href="Page2.html" onclick="colorBlue()">Set color to blue</a>
<a href="Page2.html" onclick="colorGreen()">Set color to green</a>

<script>

function colorRed() {
      sessionStorage.setItem("colorVar", "red"); 
}
function colorBlue() {
     sessionStorage.setItem("colorVar", "blue");
}
function colorGreen() {
     sessionStorage.setItem("colorVar", "green"); 
}
</script>

<!-- [This is Page 2] -->

<script>
window.onload = sessionStorage.colorVar + 'Write()';

function redWrite() {
    document.write("Your color is red!")
}

function blueWrite() {
    document.write("Your color is blue!")
}

function greenWrite() {
   document.write("Your color is green!")
}
</script>