Noxious and Aqua I think.

Also colors next to each other go well together.

Quick Silver relax would prolly go nice with Vampire force.

Yeah, pure and vampire look good but pure is a bitch to get. Same with Void and Gold me current one but again a bitch to get hold of. I had Dragon and Radioactive for a while it was rather sexy.

ecto or marine would be blue

there is no light orange. the closest thing to that is probally gold

I currently have Aqua force with Gold relax.I think it looks pretty nice!

Your best bet is to try out different colours with the in-game shop,thats what i do.

I just have ecto primary and marine secondary

i think it looks hot in my oponion.

any light colors would go nice with quickisilver in my opinion

Amber is light orange Bluesaint.

Oh, Sorry my bad, But gold is too.

What would go good with ecto and marine gradients?

Not at all really, too much of one tint looks hideous

Try going for a mix of a neutral color and a brighter color.

Like Pure and Acid.
My personal favorite :P