1.

<el-tree
  :data="data"
  :props="defaultProps"
  node-key="id"
  :default-expanded-keys="defaultExpanded"
  :render-content="renderContent"        ///////////注意这里
  @node-click="handleNodeClick"/>

2.

data:

defaultProps: {
  children: 'children',
  label: 'name'
},

methods:

//   判断 type     选择自己想要的样式   

renderContent(h, { node, data, store }) {
  return(<span class={data.type == 1?'selling-category':(data.type == 2?'seckill-category':'common-category')} style="font-size:14px;cursor:pointer">{node.label}</span>)
},

注意：renderContent中需要使用 jsx 语法

https://blog.csdn.net/weixin_33911824/article/details/93575421

3.

css:

.selling-category{
  color:#7195FA;
}
.seckill-category{
  color:#D874FA;
}
.common-category{
  color:#FC5D5D
}