osu-profile-gamemode-background-changer.user.js

// ==UserScript==
// @name         osu! Profile GameMode Background Changer
// @namespace    https://github.com/omkelderman/
// @version      1.0
// @description  Change user-profile background according to game-mode
// @author       Olle Kelderman
// @match        https://osu.ppy.sh/u/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // std is the only one with a color atm
    var colors = ['', '#ffffcc', '#ccffcc', '#ccffff'];

    function updateGameModeBg() {
        console.log("GAAAAME MOOOOOODE: " + activeGameMode);
        var color = colors[activeGameMode] || '';
        $('.bodytopbg').css('background', color);

        // remove pippi if there is a custom color
        $('#coolheader').toggle(color === '');
    }

    // catch game-mode changes
    $('.profileGameModeButton').click(updateGameModeBg);

    // apply on page-load
    updateGameModeBg();
})();