Rca sound system hooked up to the tv the dvd pictures is black and white

I see three possible problemos:

1: You are using a composite connection and your tv is downright crappy at displaying a composite feed--I know mine is. Try upgrading to component if your tv supports it. If not use a s-video connection.

2: You are using an s-video connection and there is some connection problem, either in the DVD player, the cable connectors, the cable itself, or the s-video input on your tv. Upgrade to component if your tv supports it, otherwise try the cable and DVD player out on another tv to see if the tv is the problem, or use the cable on a different DVD player to see if the cable is the problem.

3: You are using component input only two of the cables are loose OR you are only using the green-colored cable. Either plug in all three component cables (red, green, blue) or try pressing the cables in while watching to see if that fixes it. You may need a better cable, some of them are crappy at staying in.