Text Rainbow

A website designer wants to create a colourful webpage that displays the six HTML heading sizes in the colours of a rainbow.

You have been provided with the HTML code for the webpage. Your task is to add internal CSS to change the colour of each heading.

<html>
<head>
    <title>Text Rainbow</title>
</head>
<body>
    <h1>Red</h1>
    <h2>Orange</h2>
    <h3>Yellow</h3>
    <h4>Green</h4>
    <h5>Blue</h5>
    <h6>Purple</h6>
</body>
</html>
<style>
    h1{
        color: ?????;
    }
</style>