[OPEN] Ext.toolbar.Breadcrumb is not visible with Gray or Classic theme

Here is the simple code to replicate the problem (similar to the Kitchen Sink example):

Code:

        Ext.define('KitchenSink.store.Files', {
            extend: 'Ext.data.TreeStore',

            root: {
                text: 'Ext JS',
                expanded: true,
                children: [
                    {
                        text: 'app',
                        children: [
                            { leaf: true, text: 'Application.js' }
                        ]
                    },
                    {
                        text: 'button',
                        expanded: true,
                        children: [
                            { leaf: true, text: 'Button.js' },
                            { leaf: true, text: 'Cycle.js' },
                            { leaf: true, text: 'Split.js' }
                        ]
                    },
                    {
                        text: 'container',
                        children: [
                            { leaf: true, text: 'ButtonGroup.js' },
                            { leaf: true, text: 'Container.js' },
                            { leaf: true, text: 'Viewport.js' }
                        ]
                    },
                    {
                        text: 'core',
                        children: [
                            {
                                text: 'dom',
                                children: [
                                    { leaf: true, text: 'Element.form.js' },
                                    { leaf: true, text: 'Element.static-more.js' }
                                ]
                            }
                        ]
                    },
                    {
                        text: 'dd',
                        children: [
                            { leaf: true, text: 'DD.js' },
                            { leaf: true, text: 'DDProxy.js' },
                            { leaf: true, text: 'DDTarget.js' },
                            { leaf: true, text: 'DragDrop.js' },
                            { leaf: true, text: 'DragDropManager.js' },
                            { leaf: true, text: 'DragSource.js' },
                            { leaf: true, text: 'DragTracker.js' },
                            { leaf: true, text: 'DragZone.js' },
                            { leaf: true, text: 'DragTarget.js' },
                            { leaf: true, text: 'DragZone.js' },
                            { leaf: true, text: 'Registry.js' },
                            { leaf: true, text: 'ScrollManager.js' },
                            { leaf: true, text: 'StatusProxy.js' }
                        ]
                    },
                    {
                        text: 'core',
                        children: [
                            { leaf: true, text: 'Element.alignment.js' },
                            { leaf: true, text: 'Element.anim.js' },
                            { leaf: true, text: 'Element.dd.js' },
                            { leaf: true, text: 'Element.fx.js' },
                            { leaf: true, text: 'Element.js' },
                            { leaf: true, text: 'Element.position.js' },
                            { leaf: true, text: 'Element.scroll.js' },
                            { leaf: true, text: 'Element.style.js' },
                            { leaf: true, text: 'Element.traversal.js' },
                            { leaf: true, text: 'Helper.js' },
                            { leaf: true, text: 'Query.js' }
                        ]
                    },
                    { leaf: true, text: 'Action.js' },
                    { leaf: true, text: 'Component.js' },
                    { leaf: true, text: 'Editor.js' },
                    { leaf: true, text: 'Img.js' },
                    { leaf: true, text: 'Layer.js' },
                    { leaf: true, text: 'LoadMask.js' },
                    { leaf: true, text: 'ProgressBar.js' },
                    { leaf: true, text: 'Shadow.js' },
                    { leaf: true, text: 'ShadowPool.js' },
                    { leaf: true, text: 'ZIndexManager.js' }
                ]
            }
        });

        var store = new KitchenSink.store.Files();
        
        var win = new Ext.window.Window({
                width: 400,
                height: 200,
                items: new Ext.toolbar.Breadcrumb({
                    store: store,
                    selection: store.getRoot().childNodes[4].childNodes[7]
                })
            });
        
        win.show();

[OPEN] Ext.toolbar.Breadcrumb is not visible with Gray or Classic theme