Diving Log 6.0 supports several themes and an accent color, which you can choose from the menu “File > Preferences > Appearance”:
For users coming from version 5.0, there is also a “Diving Log 5.0” theme, which should offer a familiar look and feel:
And for users who run Windows in classic style (only available in Windows 7 or lower), Diving Log 6.0 will use automatically a classic theme:
Diving Log 6.0 still runs and looks good on Windows XP: