Hi ladwwd56,
Welcome to the Support Communities!
Is it possible that you may have an Accessibility feature called "White on Black" turned on?
See page 244 of the iPhone User Guide PDF:
http://manuals.info.apple.com/MANUALS/1000/MA1539/en_US/iPhone_iOS4_User_Guide.p df
White on Black
Use White on Black to invert the colors on the iPhone screen, which may make it easier to read the screen. When White on Black is turned on, the screen looks like a photographic negative.
Invert the screen’s colors: In Settings, choose General > Accessibility and tap the “White on Black” switch.
If that is not the case, try restarting / resetting the iPhone:
iOS: Turning off and on (restarting) and resetting
http://support.apple.com/kb/HT1430
If that does not resolve the issue, refer to page 146 in the iPhone User Guide to Reset All Settings:
iPhone User Guide for iOS 7
manuals.info.apple.com/MANUALS/1000/MA1565/en_US/iphone_user_guide.pdf
Happy New Year!
- Judy