Remove some more Sky examples that don't run

sky/examples/color/color-sample.sky

-<!--
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
--->
-<import src="/sky/framework/sky-element/sky-element.sky" as="SkyElement" />
-
-<sky-element name="color-sample" attributes="color:string">
-<template>
-  <style>
-    :host {
-      background-color: {{ color }};
-    }
-  </style>
-</template>
-<script>
-module.exports = class extends SkyElement {
-  created() {
-    this.color = "blue"; // "#FFFFFF";
-  }
-}.register();
-</script>
-</sky-element>