Initial screen.

Active field highlighted in teal with its text inverted to white. 

Example of a field error. Field highlighted in pink with the error message in red offset on purpose to make it impossible for the user to miss. 

User tries to type in a password that doesn't adhere to password guidelines.

Gets an error that clearly tells the user what the issue with the password is.

Example of an automatically generated strong password obtained by clicking the "Generate strong password" link. Shown in plain text for a few seconds so that the user can make sure it's what they intended and copy it.

After a few seconds the password text turns into dots for privacy reasons.

User selects their gender by clicking the appropriate gender icon.

Information that wasn't essential to create an account is split into the second page. That way, if the user jumps off after the first page the account has already been created and the captured contact info can be used to remind them to come back to finish filling out the remaining account info. Day and Year fields aren't dropped downs because that makes it quicker to fill them in. A picture challenge is used to prove that the user is human instead of Captcha. The optional fields are moved to the very end of the form.

This was the original form that I used as a starting point.