No, this is the perfect example of a bad ux. IE - Having a navigation bar in blue on the homepage but red on the internal pages is not acceptable.

Consistency is always good. I can see an argument for having certain types of breadcrumbs in the form of progress bars for instance (Ie - to show progress).

If your site/app has a good, clean url/directory setup then you'll have no need for breadcrumbs. (ie - www.site.com/shop/mens/ is better than just www.site.com/mens/ )

No, this is the perfect example of a bad ux i.e. - Having a navigation bar in blue on the homepage but red on the internal pages is not acceptable.

Consistency is always good. I can see an argument for having certain types of breadcrumbs in the form of progress bars for instance (Ie - to show progress).

If your site/app has a good, clean url/directory setup then you'll have no need for breadcrumbs. (ie - www.site.com/shop/mens/ is better than just www.site.com/mens/ )