Theme

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Theme'
});

templates.application.hbs

<style>
	body {
   font-family: helvetica
  }
  
  .box {
    width: 100px;
    height: 100px;
    border: 1px solid black;
    background-color: {{primaryColor}};
  }
  
  .header {
  	font-size: 30px;
    color: {{primaryText}}
  }
  
</style>

<div class="header">Theme</div>
<div class="box"></div>

<br>
<label>Primary Color
	<input type="color" oninput={{action (mut primaryColor) value="target.value"}}>
</label>
<br>
<label>Primary Text Color
	<input type="color" oninput={{action (mut primaryText) value="target.value"}}>
</label>

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}