Here is my code. I want to change some fields background color according to the result of a rpc call. But the change only happens when I switch the mode between edit and save.It should be changed when I open this record.

Any idea?

var render = listRender.extend({
        init: function () {
            this._super.apply(this, arguments)
        },
        async _render() {
            const result = this._super.apply(this, arguments);
            var fields = [];
            for (let index in this.arch.children) {
                if (this.arch.children[index].tag === "field") {
                    fields.push({"field_name": this.arch.children[index].attrs.name, "index": index});
                }
            }
            var self = this;
            this.arch.children[36]["attrs"]["class"] = "red_color";
            var infos = await this._rpc({
                model: "purchase.order",
                method: "is_updated",
                args: [{"fields": fields, "id": this.state.res_ids}]
            });
            infos.data.forEach(ele => {
                this.arch.children[parseInt(ele["index"])]["attrs"]["class"] = "red_color";
            })
        },
    });