Using Textbox.io -custom styles dropdown

HTML

<script src="http://fonts.googleapis.com/css?family=Lato:400,900italic|Arvo:400,700,400italic|Ubuntu|Josefin+Slab"></script>
<script src="http://jsfiddle.net/textboxio/4y98k8ny/"></script>
<script src="https://s3.amazonaws.com/static.ephox.com/jsfiddle/textboxio/textboxio.js"></script>
<form>
    <textarea id="mytextarea"></textarea>
</form>

CSS

#mytextarea {
    margin:10px;
    height:200px;
}

.ephox-polish-editor-container .ephox-chameleon-toolstrip {
    background-color: #ffff !important; // I am not sure if you will need !important
}

.ephox-polish-editor-container .ephox-chameleon-toolbar:first-child {
    box-shadow: inset 0 -.5em 1em #536872 !important; // I am not sure if you will need !important
}

JavaScript

textboxio.replace('#mytextarea',{
    ui: {
        toolbar: {
            // Define which items you'd like in the toolbar here,  and their
            // ordering. See http://docs.ephox.com/display/tbio/Command+Item+IDs 
            // for a list of available commands
            items: ['undo', 'insert', 'style', 'emphasis', 'align', 'listindent', 'format', 'tools', 'language']
        }
    }
});alert(ed.content.get());
});