how to change colour of 'manage' field?

By mistake I changed the color of some fields in my DocuSign account and now I can’t read these fields anymore because its black on dark blue. But I can’t find the option anymore to change it back.

For example if I click on ‘Manage’ the field ‘start now’ is in these colours. Or also if I am creating an envelope the ‘next’-button is unreadable. The same is happening also on the page before you send of an envelope with the ‘send’ button. 

Please help me on how to fix this problem. 

Thank you!