I am not sure if this is a DVD or Home Theater question, but since I am running everything through my receiver I am going with HT.
I got everything in my home theater system to work EXCEPT DVDs only play in black & white. Cable and VCR are in color, so I assume receiver to TV connection is not an issue.
I connected the DVD player to the receiver via the component connections (I just used extra cable that fit the connections and this may or may not be an issue).
I have read the DVD player and receiver manual numerous times (and found many other options I never would have known) but cannot find anything that could solve the issue.
Component connection is where the problem lies. It is split up into essentially red, blue and b+w signals through the three connections. More than likely the wire you have will work, it just sounds like you have the connections differing from the dvd to the monitor. If you check these and thats not the issue then definitely get the appropriate wire to do the job.