I presume you didn't mean to post this here :lol:
My recommendation for painting very dark uniform colours like this is not to think of them as blue, you'll be aiming for 'blue' all the time in your head as you mix - when in fact the colour is much more grey than blue usually (period accounts of Union uniforms repeatedly say how dull it looked to their eyes for example).
Here I would suggest you basecoat in a very dark mixture of something like Ultramarine and Burnt Umber, shadow with straight black, highlights mixed from the base mixture with a touch of a skintone colour perhaps (a red earth + white would do just as well). Remember, you're not aiming for an obvious blue colour in the lighter values.
I would not go too light on the highlighting myself, although I realise this is 1/35 so you have to push the contrast a bit.
Einion