Interesting question - with (like most interesting questions) no simple answer.
There have, of course, been two German sailing schoolships named Gorch Fock. The first one, built in the thirties, went to the Soviet Union as war reparations and was renamed Tovaritsch. If I'm not mistaken, she's currently under restoration somewhere or other; I confess I've lost track of that story. The second ship was launched in 1958 and currently is in service with the German navy.
I've never compared the plans of the two vessels. They certainly look extremely similar in photos - but just how similar they are in real life I honestly don't know.
I haven't looked at the Minicraft 1/350 kit in a long time. I know it was one of the series that Imai released in conjunction with the notorious "tall ships" extravaganza in 1976. And I know Imai recycled hulls and various other parts to make several "different" kits - the USCG Eagle and the Portuguese Sagres, for instance. (Those ships are in fact near-sisters - but not quite. As we've discussed several times here in the Forum, all those German schoolships of the thirties differed in length.)
I'm wondering whether Imai used that same hull in its Gorch Fock kit. If so, it's probably a reasonably accurate rendition of the first ship - the one from the thirties. I have an extremely vague recollection, though, that there may have been a kit specifically labeled "Gorch Fock II" (and another one labeled Tovaritsch) in the Imai series. If so, did Imai produce a different set of parts to represent the 1958 ship accurately? I have no idea.
Anyway, as for the color scheme - the best I could come up with (going the same route Powdermonkey did, I imagine) is the ship's German-language website: http://www.marine.de/portal/a/marine/kcxml/04_Sj9SPykssy0xPLMnMz0vM0Y_QjzKLNzKODwxxBcmB2d5mIfqRcNGglFR9X4_83FR9b_0A_YLciHJHR0VFAFDI-qo!/delta/base64xml/L3dJdyEvd0ZNQUFzQUMvNElVRS82XzIzX1FTVg!! . On the homepage is a photo of the ship dated 2007; it seems to show all the spars, down to deck level, in "spar color" or something similar to it. (I think that color terminology is distinctive to the USCG, but the color in the photo certainly looks like it.) If you click on that photo you can enlarge it to full-screen size and see quite a few details in it - probably enough to turn a 1/350 model into a nice exercise in frustration.
Later edit: the web gremlins are at work. If you click on the above link, you get sent to the homepage of the German Navy - not the page of the Gorch Fock. The quickest route to the latter seems to be the one I used: start with the Wikipedia article: http://en.wikipedia.org/wiki/Gorch_Fock_(1958) . Scroll down to the bottom of that page and click on "Official homepage of the Gorch Fock." That will bring up the picture I was talking about earlier.
The German navy website does have a search function. Type in "Gorch Fock" and you'll get some news releases about her - including one about the appointment of a new CO. It's accompanied by a quite recent photo, which does show the tan-colored lower masts. I didn't try that search function beyond that, but it might well yield some other useful stuff.
I don't imagine any of that helps much. Sorry.