Firstly, Nils, I think your command of English far exceeds my command of Swedish! ;^) Consider, for example, your correct use of the idiom "spot-on"!
Back on topic, since delving into this MillFalcon hot-bed of knowledge (also for my Hasbro model) and finding the various image archives online, I have found it fascinating just how layered the finish was on the 5-footer. I've seen at least three different basic color layers: a blackish primer (I'm assuming since it seems to be underneath all the missing parts), a yellow coat visible in so many chipped places under the top layer, a grey or white paint 'base' color. Then there is the applied dark grey, yellow & red panels, the spattered weathering, the physical abrasion weathering, "smoke" effects, some dark washes... so many different effects.
Always at issue is what are the specific "conditions" you will depict on your model: the "on film" version (and which one will you have today? Special Edition? Blu-Ray?), the one apparent from the actual miniature (good color reference being taken by flash illuminated pictures, assuming your computer monitor is presenting a fairly true color representation... ha!) or just the one you might think looks best. See what I mean? It is completely subjective, at least to the point that it probably should be some shade of light grey or white, suitably weathered. Unless we have access to the actual paint specification used by ILM, which I don't believe anyone has, you must simply decide what looks best. If you want to be cautious, do some experiments with different colors on a test "board" (cheap styrene plastic signs are a good source...) and at least quantify your methodology. You could then also use it for testing weathering techniques as well as testing the color schema under your planned display lighting. It would also make an interesting exercise to share here on RPF if you'd like. In the end, I suspect you will be happy with the results if you put in the effort.
Remember, no tech order exists for the MF, no matter what the Haynes folks say!
Regards, Robert