I have successfully changed the default homepage to index3.html and everything works fine and loads in the desired theme except the login page/form after clicking on a deeplink link. after login the correct theme is applied. How do I change this behaviour? update: I have also set the constant to index3.html
Do you have an IndexPage constant in your deeplink module?
misread your original question. The login and error page are in the resources directory, you should adjust them manually to your styling (for example by including another css file)