How should I filter items of a user?

I am using Ember 1.13.2 and Ember Data 1.13.4. The API conforms to JSON API format (http://ift.tt/1Me9yCb).

A user has many items. Doing {{model.items}} in the template will return ALL items of the user.

What if I also need to display ONLY blue items from the user. How should I go about this?

// Route
import Ember from 'ember';

export default Ember.Route.extend({
  model(params) {
     // Executes: http://localhost:3099/api/v1/users/5
    return this.store.findRecord('user', params.user_id);
  }
})

// Template
firstName: {{model.firstName}} - works
<br>items: {{model.items}} - works
<br>blue items: {{model.items}} - what do we do about this?

// app/models/user.js
import DS from 'ember-data';
export default DS.Model.extend({
  items:        DS.hasMany('item', { async: true }),
  firstName:    DS.attr('string')
});

// app/models/item.js
import DS from 'ember-data';
export default DS.Model.extend({
  user:           DS.belongsTo('user', { async: true }),
  name:           DS.attr('string')
});