Estoy tratando de crear un buscador de contraste de color javascript

 function gamma_correction(r,g,b) { r=calc(r) g=calc(g) b=calc(b) r*=0.2126 g*=0.7152 b*=0.0722 return r+g+b } function hexToRgb(hex) { result = /^#?(\[af\\d\]{2})(\[af\\d\]{2})(\[af\\d\]{2})$/i.exec(hex) return result ? { r:parseInt(result\[1\],16), g:parseInt(result\[2\],16), b:parseInt(result\[3\],16) } : null; } function calc(c) { let t = 0.03938; c/=255; return (c < t)? c /= 12.92: c = (((c + .055) / 1.055) ^ 2.4); } let x=document.getElementById('colorpicker') x.addEventListener('change',()=\>{ var {r,g,b} =hexToRgb(x.value) return document.getElementById('L1').innerText=gamma_correction(this.r,this.g,this.b) }); let y =document.getElementById('colorpicker2') y.addEventListener('change',()=\>{ var {r,g,b} =hexToRgb(y.value) return document.getElementById('L2').innerText=gamma_correction(this.r,this.g,this.b) });