Someone else had a similar situation and posted already. Try a search to see exactly what the answer was. Support probably will not get answer back to you until after the holidays (assuming you posted there).
In a nutshell, from what I remember reading, you are out of luck on this. The CD states that buying a new ship loses the orange goliath. Remember, too, that the orange color was not the only thing being bought... there was the ammo and stuff.
A similar situation would be for someone to purchase uri and directly buy an elite ship with it. If that person then bought a Big Boy with credits, the uri you spent cash to buy is effectively gone. Since it was a choice, and not a glitch, they are not going to be able to do anything about it. Sorry, dude.
***Updated: Just read boo ya's post and I'll cross my fingers for you and hope it works.***
In addition to the orange goliath, you get some elite equipment, x4 ammo, and a limited number of "remote refining" that saves going back to base. The ammo is nice, but you can get that or as good playing around with the Galaxy Gate generator or in spaceball. I haven't done the math, but it probably adds up on the plus side if you were to consider someone who did not already have the goli and elite stuff. But as one who has already obtained everything I would not buy it. To my mind having a color that makes you stand out makes you more of a target.
Now if they had one with unique abilities, even on a limited basis... that might be tempting. Something like a next generation cloak that has a number of charges like the jump chips would be useful. Hmm.. wonder if anyone has put that idea up in the Ideas forum...