Oracle APEX dynamic style base on domain name

Add a new process with the following PL/SQL code to the login page Before Header Section.

Pre-Rendering->Before Header->Processes

DECLARE
  v_http_host varchar2(1000);
BEGIN 
  v_http_host := lower(owa_util.get_cgi_env('HTTP_HOST'));

  if v_http_host = 'domain1.com' or v_http_host like '%.domain1.com' then
    apex_theme.set_session_style(p_theme_number=> 242, p_name => 'my_style1');
  elsif v_http_host = 'domain2.com' or v_http_host like '%.domain2.com' then
    apex_theme.set_session_style(p_theme_number=> 242, p_name => 'my_style2');
  else 
    apex_theme.set_session_style(p_theme_number=> 242, p_name => 'my_style1');
  end if;
END;