The web UI doesn't properly set the colors on form controls (text fields, text areas, combo boxes etc). If the system look and feel uses dark controls with light text (e.g. the Darklooks theme in Fedora), then the form components are still dark in Jira, but the text is set to black. This makes the input forms really hard to use as black text on a dark gray background isn't really easy to read.

See attached screenshots.

Proposed solution:
Wherever input form controls have their font color explicitly set (in CSS or HTML), the background color should also be set. Alternatively: Don't set the foreground color of input form controls at all (and leave it to the system look and feel),