Well, having read a fair bit of the series...
There is rather few info on how the ships are painted; in fact, the few comments I can remember point to an overall bare metal look.
In the SOL's case, this would be flamingo red, or possibly blueish-red, in the original, 6500m long, state. "Luckily", I can't remember any color-related comments from this time, so both box art and instructions could be taken as a possible paint job, which was simply never mentioned.
However, the Revell kit builds into the "refit" version (8000m long), which is golden (and has been shown like this on several covers); so if you want to do the kit "correctly", you'd have to paint it overall gold.
So much for canon. I'd recommend doing what you think will look good.