The QuickTimeVR model accessible by clicking below shows the relation between computer RGB space and video's YCrCb component color space. Those areas where the RGB cube stick out from the YCrCb box represent NTSC "illegal colors". But it is also important to note all the color shades in the YCrCb box that fall outside the RGB cube. This space contains component video colors that cannot actually be reproduced in RGB space.
NOTE: Clicking on the image below will begin download of a 2.5 megabyte QuickTimeVR file which may take significant time if you are using a dial-up connection. It may also require that you have the QuickTime Player plugin version 4 or later player installed on your system in order to properly view the QTVR model.
Once the model the QuickTime VR file has finished downloading, you may click-drag the color spaces cubes in order to change their orientation for viewing.