Blue iMac trackpad

I purchased an open box blue iMac ... returned item... without a trackpad. I'd like to add the matching blue anodized trackpad with white top. I called Apple support about something else and this came up. He connected me with Ruby. (RECONNECT 1) Ruby informed me that it could be done if I had a purchase number, and that she would connect me to AppleCare ... they could do this, Ruby said. (RECONNECT 2) I was connected by the 'system' to someone who said oops wrong department, let me get you to the correct number. I was so confident after speaking with with Ruby I stopped getting names and departments. So I blithely agreed to be reconnected. (RECONNECT 3) The next guy said he was 'pre-sales' and I needed to talk to "post-sales"... He could only offer white or black.... so again I trustingly took no name.. and (RECONNECT 4) was connected to a lady in post sales who "googled it." This lady also checked the website (black only). "Anything else I can do for you?"