I don't design Vasudan capital ships.
Plus I'm not a modeller.
But, if you want my two-cents worth, I would actually say look at rocks.
I know this sounds weird, but I felt that a lot of Vasudan ships take design inspiration from rocks. Some are rocky, sort of "rumbly", if that makes sense. Take a rough, jagged structure with some crystalline parts (those crystals are definitely there in the retail Vasudan ships IMHO) and then smooth it way down. If you look at the large, flat parts of the Sobek's hull, for instance, it looks like a polished stone mosaic. At least it does to me.
Use tan, pinkish, or dark brown for the main hull, and cool blue or purple or pink for highlights. Maybe a little luminescent green, you can see it on the Taurus and Sekhmet.
Anyway, that's just my ideas. Good luck, I hope you're inspired to make something totally rad!