THIS IS FOR STYLE DEVELOPERS / APPLICATION DEVELOPERS ONLY
CheckColorRoles color theme for KDE 4 is used to check correct usage of so called "color roles" in styles. Violations are visible via non-matching foreground/background combinations.
Additionally, styles or applications that use hard coded black or white colors can be easily detected.
If you find a style/application that clearly violates the color rules, you could redirect its author to this color theme and point her to the problem.
The screenshots are from an old Oxygen (default KDE style) version. The version shipped with KDE 4.5 or later should have no violations. If you still find some, please report it to the KDE bug tracker.