My tv is sharp aquos. When i put the plug of our newly brought karaoke dvd, the video is black and white. But other channels a

Solution
Seems like you are connecting component connections wrong or are trying to use component connections with a composite input. Or vice versa. Since you did not list any details, I am guessing you are using the standard RCA video/audio connections, composite has left/right audio and a video connection, component has left/right audio and three video connections, if they are not connected properly, you get a black and white image.

Like this https://www.lifewire.com/shared-composite-component-video-input-connections-4103732
Seems like you are connecting component connections wrong or are trying to use component connections with a composite input. Or vice versa. Since you did not list any details, I am guessing you are using the standard RCA video/audio connections, composite has left/right audio and a video connection, component has left/right audio and three video connections, if they are not connected properly, you get a black and white image.

Like this https://www.lifewire.com/shared-composite-component-video-input-connections-4103732
 
Solution