These look really good Charles. We were talking about colour theory the other night and I think you've done a really good job of applying it. I don't believe I knowingly adhere to it very much, but like I was saying, it can be tricky (maybe not so much in design but definitely in miniature painting) to get complimentary colours at opposite sides of the wheel to actually appear complimentary and not garish. A blue and orange elf would be garish.
The way you've done it though really works, and suits my tastes. The models are understated, clean and naturally coloured but the subtleness of the blues and oranges really work together. I think you could even afford to lighten the skin up a bit (on No. 1, if you were going this way). Just to make it a bit more elvie, but it'd still be orange enough to work with the blue/white cloth work. I love the white cloth by the way. You could make the blue shading on the cloth a bit darker but when you're blending up to white over such a small area I know it can be difficult.
I like the dark skin on the witch elf, technically it's done very well. Just don't think there's enough contrast between skin and armour. If you were going for an Indian look, check this out.
This was the mini that Ian Morton posted on fb and gave me my haqq skin tone (though I kept mine a touch darker). You can see it looks almost green and lightens into orange. It looks lovely with the blue dress (white/blue would look equally as good) and, while looking sorta indian, is light enough that it would contrast well with the dark armour and hair.
Regards the blue wash on the metal. I'd stick with it because there is a way to make it work. Unfortunately I don't know it. My metals are a real weak part my game. But it can look great. Love the blue in the hair and
SW grey is a great way to highlight it. VMC wolf grey is one of my favourite pots.
But that's my t'pence. Sorry for waffling a bit. Overall I, think you're way on the right track. The witch elf (No.1) is pretty much bang on as it is. If you aren't totally happy with the skin tone, experiment a bit yet til you are. This army is gonna look great though. Ticks all my boxes in terms of paint scheme; subtle, earthy colours, very limited palette, contrast without shock, no big bright pinks, purples, yellows. And very very well excecuted. You're tackling a lot that I'm not great with, skin, metals, cloth, leather, etc. Just WFB I suppose.