A Theme for Slack or This is my theme for English B.

slack.js

// What?! http://stackoverflow.com/a/5571069/700536
function multiline(f) {
  return f.toString().
      replace(/^[^\/]+\/\*!?/, '').
      replace(/\*\/[^\/]+$/, '');
}

var overrides = multiline(function() {/*!
#messages_container {
  background-color: #dfdfdf;
}
*/});

$('head').append("<style>"+overrides+"</style>");

var audio = document.createElement('audio');
$(audio).attr('src', "http://meaganproctorkavouras.com/levi.wav");
TS.ui.sounds.new_message = audio;
TS.ui.playSound('new_message');

// Leave reset false when you say something
function say(message, skipReset) {
  if (!skipReset) {
    window.channels = [];
 
    $('a.channel_name').each(function() {
      window.channels.push($(this).attr('href').replace('/channels/', ''));
    });
  }
  
  setTimeout(function() {
    if (window.channels.length == 0) return;
    var chan = window.channels.pop();
    $('#message-input').val('/open '+chan);
    $('#message-input').parents('form').submit();
    setTimeout(function() {
      $('#message-input').val(message);
      $('#message-input').parents('form').submit();
      say(message, true);
    }, 100);
  }, 100);
}