Depending on the subject or shooting condition, colors may look different in the viewfinder compared to how they look on the LCD screen. This is a normal operation and not a malfunction.
NOTE: The color temperature of the viewfinder can be adjusted through the Viewfinder Color Temp. setting of the camera. If model-specific information is needed to do this, refer to the instructions supplied with the product. Manuals are posted on your model support page.