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<html><body><h2>JavaScript Booleans</h2><p>Return "green" if a boolean value is true, otherwise display "red":</p><p id="demo"></p><script>Boolean.prototype.myColor = function() { if (this.valueOf() == true) { return "green"; } else { return "red"; }};let a = true;document.getElementById("demo").innerHTML = a.myColor();</script></body></html>