JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<body>
<div id="red" style="background-color:red;">
 <div id="trans">
 Some text.
 </div>
</div>
    <div id="getColor_out"></div>
    <div id="getColorMod_out"></div>
</body>
</html>

JavaScript

// Color Conversion functions from highlightFade
// By Blair Mitchelmore
// http://jquery.offput.ca/highlightFade/
 
// Parse strings looking for color tuples [255,255,255]
function getRGB(color) {
        var result;
 
        // Check if we're already dealing with an array of colors
        if ( color && color.constructor == Array && color.length == 3 )
                return color;
 
        // Look for rgb(num,num,num)
        if (result = /rgb\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*\)/.exec(color))
                return [parseInt(result[1],10), parseInt(result[2],10), parseInt(result[3],10)];
 
        // Look for rgb(num%,num%,num%)
        if (result = /rgb\(\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*\)/.exec(color))
                return [parseFloat(result[1])*2.55, parseFloat(result[2])*2.55, parseFloat(result[3])*2.55];
 
        // Look for #a0b1c2
        if (result = /#([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})/.exec(color))
                return [parseInt(result[1],16), parseInt(result[2],16), parseInt(result[3],16)];
 
        // Look for #fff
        if (result = /#([a-fA-F0-9])([a-fA-F0-9])([a-fA-F0-9])/.exec(color))
                return [parseInt(result[1]+result[1],16), parseInt(result[2]+result[2],16), parseInt(result[3]+result[3],16)];
 
        // Look for rgba(0, 0, 0, 0) == transparent in Safari 3
        if (result = /rgba\(0, 0, 0, 0\)/.exec(color))
                return colors['transparent'];
 
        // Otherwise, we're most likely dealing with a named color
        return colors[$.trim(color).toLowerCase()];
}
 
function getColor(elem, attr) {
        var color;
 
        do {
                color = $.curCSS(elem, attr);
 
                // Keep going until we find an element that has color, or we hit the body
                if ( color != '' && color != 'transparent' || $.nodeName(elem, "body") )
                        break;
 
                attr =...