JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/knockout/3.0.0/knockout-min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/knockout.mapping/2.3.5/knockout.mapping.js"></script>
<table>
<thead>
  <tr data-bind="foreach: columns">
    <th data-bind="text: headerText, click: sortBy, css:  sortClass"></th>
  </tr>
</thead>
</table>

CSS

.no_sorting{
    
}


.sorting_asc{
    color:green
}

.sorting_desc {
    color:red
}

JavaScript

var Parent = function(){
    var self = this;    
    self.columns = ko.observableArray([
        new Column("col1", self),
        new Column("col2", self),
        new Column("col3", self)
    ]);
            
}

var Column = function(headerText, parent){
    var self = this;
    self.parent = parent;
    self.sortDirection = ko.observable();
    self.headerText = ko.observable(headerText);
    self.sortClass = ko.computed(function(){
        if (!self.sortDirection()){
            return 'no_sorting';
        }
        return self.sortDirection() == 'ascending' ? 'sorting_asc' : 'sorting_desc';
    },self);
    
    self.sortBy = function(){
        if (!self.sortDirection()) {
            self.sortDirection('ascending');
        } else if (self.sortDirection() === 'ascending'){
            self.sortDirection('descending');
        } else {
            self.sortDirection('ascending');
        }
    }
}

ko.applyBindings(new Parent())