MediaWiki:Common.js

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/* Any JavaScript here will be loaded for all users on every page load. */

var bodyColour = window.getComputedStyle(document.querySelector("body"))
                    .getPropertyValue("background-color").match(/rgba?\((.*)\)/)[1].split(",").map(Number);
var usingDarkTheme;
if (bodyColour[3] === 0) {
    usingDarkTheme = false;
} else {
    usingDarkTheme = bodyColour.reduce(function accum(a,b){return a+b;}) < 255 * 1.5;
}

if (usingDarkTheme) {
	document.querySelectorAll("img").forEach(function turnGrey(image) {image.style.backgroundColor = "grey";});
}