JSFiddle - React, Tailwind, and code Playground

HTML

<form enctype="multipart/form-data" name="brief_form_new" id="brief_form_new_test" action="#" method="post" novalidate="novalidate" ng-app="briefApp" ng-controller="briefController" ng-submit="submitForm($event)" >
            <textarea   type="text" 
                        name="message_new" 
                        rows="5" 
                        cols="50" 
                        class="main_field"
                        placeholder="Я хочу... *" 
                        style="width: 426px;" 
                        title="Заполните поле" 
                        ng-model="message" 
                        message-validate 
                        required></textarea>

            <input 	type="file" 
            		size="1" 
            		name="attachment" 
            		value="" 
            		id="fileUploadField" 
            		ng-model="attachment"
                    attachment-validate />

            <input  type="text" 
                    name="name_new" 
                    value=""
                    placeholder="ФИО *" 
                    style="" 
                    title="Заполните поле" 
                    class="brief_name main_field" 
                    ng-model="name" 
                    name-validate 
                    required />

            <input type="email" 
                    name="email_new" 
                    value=""
                    placeholder="E-mail *" 
                    style="" 
                    title="Заполните поле" 
                    class="brief_email main_field" 
                    ng-model="email" 
                    email-validate 
                    required />

            <input type="text" 
                    name="phone_new" 
                    value=""
                    placeholder="Телефон *" 
                    style="" 
                    title="Заполните поле" 
                    class="brief_phone main_field" 
                    ng-model="phone" 
                   ...

CSS

textarea.ng-valid,
input.ng-valid{
	background: #fff;
}

textarea.ng-invalid,
input.ng-invalid{
	background: #f00;
}