Blue links on GitLab don't pass color audit

WCAG 1.4.1 Use of Color requirements state:

1.4.1 Use of Color: Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. (Level A)

As per discussion on gitlab-design#291 (comment 156758886), the blue text links in our UI do not meet this requirement.