Check your connections and the ports you are using. How are they connected? Color information is u sually on a separate wire than the picture, you are either not plugging in a needed cable, or a cable or pin(s) are bad on whatever you are using to connect the laptop to the TV.
It is not the connection because I have another Laptop that works perfectly with the same s video cable.
Should have put that in the post, we can't tell what you tried already, if you post the things you did try, will save us a lot of time going over stuff.
Could be the laptop connector then. outside of setting your video to black and white in software, the only way you would get pictures without color informatin is with a bad cable or connection. If you can, check the laptop with another TV, if that is also B&W, there is an issue with your laptop connnector. If the TV is an HDone, it should have a VGA connectin or DVI/HDMI, use those with the laptop in place of the S-Video. S-Video is not good enough to transmit good picture quality from a computer resolution standpoint.