New Twiddle

products.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  queryParams: ['color'],
  color: null
});

products.index.controller.js

import Ember from 'ember';

const {
  computed,
  inject,
  set
} = Ember;

export default Ember.Controller.extend({
  productsController: inject.controller('products'),
  color: computed.alias('productsController.color'),
  
  actions: {
    setColor(color) {
      set(this, 'color', color);
    }
  }
});

products.index.template.hbs

<h2>Product index</h2>

<p>
  {{link-to 'shirts' 'products' 'shirts' (query-params color=color)}}
  {{link-to 'pants' 'products' 'pants' (query-params color=color)}}
  {{link-to 'shoes' 'products' 'shoes' (query-params color=color)}}
</p>

<h3>Color picker</h3>

<button {{action 'setColor' 'green'}}>green</button>
<button {{action 'setColor' 'orange'}}>orange</button>
<button {{action 'setColor' 'blue'}}>blue</button>

products.route.js

import Ember from 'ember';

export default Ember.Route.extend({
});

products.template.hbs

{{outlet}}

router.js

import Ember from 'ember';
import config from './config/environment';

const Router = Ember.Router.extend({
  location: config.locationType
});

Router.map(function() {
  this.route('products', { path: '/t/:taxon' }, function() { });
});

export default Router;

twiddle.json

{
  "version": "0.5.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.2.0",
    "ember-data": "2.2.0",
    "ember-template-compiler": "2.2.0"
  }
}