E11000重复键错误索引

Question

所以我有这个Schema有一个数组

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

let colorsSchema = new Schema({
    value: String
});

let sizesSchema = new Schema({
    value: String
});

let tshirtSchema = new Schema({
    id: { type: String, unique: true },
    name: String,
    url: { type: String, unique: true },
    colors: [colorsSchema],
    sizes: [sizesSchema],
    available: Boolean
}, { versionKey: false });


module.exports = mongoose.model('Tshirt', tshirtSchema);

当我插入新文档时，它给出了一个错误说

 E11000 duplicate key error index: wwc.tshirts.$sizes.value_1 dup key: { : "L" }

我尝试过给字段唯一索引，但错误仍然存​​在。