My 5.6 inch colour screen starts but only black and white shows

Well it sounds like you un-seated the cable that send the picture to to the monitor. The reason you are only getting a white screen is that the backlight is on but there is no data coming through to display.
The cable usually is a ribbon that fits into a slot. The slot then locks by pushing down on the cable and that makes the connection. It is easy to pull this cable out of the slot slightly (or all the way) and this will cause the problem that you are experiencing.
I'm not sure of your exact model but the cable and connection looks something like this:http://mwolk.com/blog/wp-content/uploads/2009/06/laptop_screen_replacement_datacable.jpg
As for fixing your wireless, you usually don't need to do anything to the laptops display. You should be able to remove the bottom cover and access the wireless card from there. The antenna are the black and white wires that are coming off the wireless card.
You can check those connections as well as, in most cases, remove the card and replace it with one that works. This should be a picture of your model or similar, you can see where the wireless card is located:http://www.insidemylaptop.com/images/Acer-Aspire-5610z/lapatop-disassembly-03.jpg