If you haven't removed the widget from the widget screen, do try that. Press the circle with a plus on the lower left and then the x on the top left corner of all the stock widgets on your dashboard (you can add more than one). If it's still broken when you add it fresh to the dashboard, you'll have to poke it a bit harder.
The widget isn't going to like this - so you'll have to manually clear out the file where the stocks are recorded.
Get ready to log out so save all your work and quit all apps.
Go to the folder below in Finder using this command (or the Go menu) shift+command+G
~/Library/Preferences
Move these two files only to your desktop.
widget-com.apple.widget.stocks.plist
widget-com.apple.widget.stocks.plist.lockfile
Then log out shift+command+Q
When you log back in (or reboot), the widget will make a new container to store your stocks and things should be better. This little dance is called setting aside your preferences (plist files) and starting again with the defaults.
If it works, you can trash the two files on your desktop. If not - you can move them back or not however you prefer. For an app with lots of settings, it's nice to be able to move back the ones you prefer once you've ruled out that file as causing you some pain or other.
If I understand the question correctly, this is an easily doable through normal terminal preferences.
Go to terminal>preferences>startup
Here you can set the default behavior regarding window color scheme, including what color scheme new windows use.
Best Answer
You can restore it from your backup. Because you wouldn't start deleting bits of the system with a third-party app without making sure you had a backup.
Failing that, you can reinstall the OS over the top of your existing installation, and all your files, apps and settings will still be in place. This will make sure that anything else important that ApplCleaner has deleted will be restored.
Some people do this from time to time, just to make sure nothing's got corrupted or missing.