我不认为你可以使用 aclass来做到这一点,但是试试这个
<div ng-app="test-app" ng-controller="MyController" theme-wrapper="{{mainColor}}">
    <div class="has-main-color">Top1</div>
    <div>Child 1</div>
    <div class="has-main-color">Top1</div>
    <div>Child 1</div>
    <div class="has-main-color">Top1</div>
    <div>Child 1</div>
    <br />
    <input type="button" value="Red" ng-click="color('red')" />
    <input type="button" value="Green" ng-click="color('green')" />
    <input type="button" value="Blue" ng-click="color('blue')" />
</div>
JS
var app = angular.module('test-app', []);
app.controller('MyController', function($scope, $rootScope, $timeout){
    $scope.mainColor = 'grey';
    $scope.color = function(color) {
        $scope.mainColor = color;
    }
});
app.directive('themeWrapper', function(){
    var counter = 0, regex = /^theme-wrapper-\d+$/;
    return {
        restrict: 'A',
        link: function(scope, elm, attrs){
            attrs.$observe('themeWrapper', function(value){
                var className = 'theme-wrapper-' + (counter++);
                $('<style>.' + className + ' .has-main-color{color: ' + value + ';}</style>').appendTo('head');
                var classes = elm.attr('class').split(' ');
                angular.forEach(classes, function(v, i){
                    if(regex.test(v)) {
                        elm.removeClass(v);
                    }
                });
                elm.addClass(className);
            });
        }
    }
});
演示:小提琴
另一个简单的修复
<div ng-app="test-app" ng-controller="MyController">
    <div style="color: {{mainColor}}">Top1</div>
    <div>Child 1</div>
    <div style="color: {{mainColor}}">Top1</div>
    <div>Child 1</div>
    <div style="color: {{mainColor}}">Top1</div>
    <div>Child 1</div>
    <br />
    <input type="button" value="Red" ng-click="color('red')" />
    <input type="button" value="Green" ng-click="color('green')" />
    <input type="button" value="Blue" ng-click="color('blue')" />
</div>
JS
var app = angular.module('test-app', []);
app.controller('MyController', function($scope, $rootScope, $timeout){
    $scope.mainColor = 'grey';
    $scope.color = function(color) {
        $scope.mainColor = color;
    }
})
演示:小提琴