JSFiddle - React, Tailwind, and code Playground

JavaScript

var next = 1;
function test() {
    var canvas = document.createElement('canvas');
    var ctx = canvas.getContext("2d");
    var imgData = ctx.createImageData(50, 50);
    imgData.data[0] = 16;
    imgData.data[1] = 0;
    imgData.data[2] = 0;
    imgData.data[3] = next;
    ctx.putImageData(imgData, 0, 0);
    var output = ctx.getImageData(0, 0, 1, 1).data;
    var A = next / 255, C = Math.round(Math.round(16 * A) / A);
    console.log(`alpha:${next}, real:${output[0]}, sim:${C}, intended:${16} match:${output[0] === C}, correct:${output[0] === 16}`);
    next++;
} 
for(var i = 0; i < 256; i++) test();