CSS
<style>
input.ng-invalid {
background-color: lightblue;
}
</style>
<body>
<form ng-app="" name="myForm">
Enter your name:
<input name="myName" ng-model="myText" required>
</form>
<style>
input.ng-invalid {
background-color: lightblue;
}
</style>
<body>
<form ng-app="" name="myForm">
Enter your name:
<input name="myName" ng-model="myText" required>
</form>