WXML

<view class="page" style="background-color:{{pageBackgroundColor}}" >
<button bindtap="changeColor" hover-class="none">点击修改背景颜色</button>
</view>

WXSS:

.page {
  display: block;
  min-height: 100%;
  width: 100%;
  position: absolute;
  left: 0;
  top: 0;
  z-index: 1;
}

JS:

Page({
  data: {
    // 自定义page对象CSS样式对象
    pageBackgroundColor: \'#5cb85c\'
  },
  onLoad: function () { },
  // 改变背景颜色
  changeColor: function () {
    var bgColor = this.data.pageBackgroundColor == \'red\' ? \'#5cb85c\' : \'red\';
    // 设置背景颜色数据
    this.setData({
      pageBackgroundColor: bgColor
    });
  }
})