This will occur if the component video cables are connected to the wrong colored jacks on either the TV or DVD player. Ensure the component video cables are connected to the appropriate colored jacks on both products: Green to Green (Y), Blue to Blue (Pb), and Red to Red (Pr).
If you have checked the connection and all the cables are connected to the appropriate matching colors, then try connecting the component video cables to another set of component video jacks on the TV - if available. Afterwards, be sure to tune the TV to the newly-connected video input to see the picture from the DVD player. However, if your TV does not have a another set of component video jacks or if the issue is not resolved, try replacing the component video cables.
If the issue is still not resolved, then the TV or DVD player may require service.  Go to Product Repair.