If you need to enable high contrast styles while you are working in your Arc site, you can enable it in your user settings.
Enter Email and Password
In the Email field , enter your email address. This is the email address where you received your invitation to create an Arc password.
In the Password field , enter your password. If you forgot your password, click the Forgot password? link .
Click the Sign In button .
Open User Menu
In the navigation menu, click the My Uploads menu  and then click the User menu .
Disable High Contrast
To disable high contrast styles, open your User Menu again and click the Disable High Contrast link.