Hi meanmuttley, thanks for the interest and really sorry about not replying/getting the PM. Need to check my settings! PegaZus is right, I don't get to visit here as much as I would like, for the main part I do different genre vehicles and can't get back to wargaming minis much, but still have a special place for them of course. They are so cool.
Anyway, the facts!!
Piranha - is a custom mix of Tamiya paints through an airbrush. I'm pretty sure "Buff" was the main ingredient, but it looks like I might have mixed some orange in to improve the color.
Devilfish - the main color is by Gaia Notes and is "Dark Yellow #2". It's a mix though, with the sides being browns and the top yellows and whites.
Best thing to do it eyeball it and have fun. The more colors you use and the more differences you make, the more interesting your minis will be.
Hope that helps, best way to get me is via the email on my site there.
Cheers,
Linc