Allow displaying SimpleSAMLphp errors on a Drupal themed page

On SimpleSAMLphp SP errors the displayed error message is confronting for a non-technical user (which is most users).

Error messages occur even on semi-regular events. e.g. my IdP is ADFS based, and it covers users @example.com. If a user tries to login to that IdP as myemail@gmail.com then the IdP sends the SP back <samlp:Status><samlp:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Responder"/></samlp:Status> - "the request could not be performed due to an error on the part of the SAML responder or SAML authority" - and SimpleSAMLphp displays the attached error page.

Ideally I'd like to be able to display error messages like this Drupal side with the site theme that users are expecting.