JSFiddle - React, Tailwind, and code Playground
HTML
<p ng-app="app" ng-controller='myCtrl as vm' ng-strict-di>
<input
type="checkbox"
ng-model="vm.clarooscuro"
ng-true-value="'claro'"
ng-false-value="'oscuro'" />
Este campo tiene el value modificado. Ahora vale {{ vm.clarooscuro }}
</p>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.4.8/angular.min.js"></script>
JavaScript
angular.module('app', [])
.controller('myCtrl', function() {
var vm = this;
vm.clarooscuro = "claro";
})