Well I naturally have thin mousy blonde hair.
Last year I died it black and it looked absoloutly AWFUL.
Not because It didnt go with my skin tone like some people said it wouldnt, infact from the front it looked lovely.
but from the back It looked like I had bald patches! My hair honestly isn't very thin, its maybe a little thinner than average but not very thin at all. So I would say dark hair with a light skin tone looks awwwful.
To make your hair look fuller and thicker, choose something close to your skin shade:
very pale white skin: ash blondes and light browns(colour with a blue undertone.
Pinky tint/ pale white: Strawberry blonde
average white skin tone: any of the previously listed hair colours.
Olive skin tone: light-medium brown(highlights look nice too)
Slightly bronzey brown: Medium brown to medium dark chocolate tones(red tones work well)
Brown skin tone: darkest brown to black.
very dark skin: ash black/ redish black/ automatic black/ cosmic blue.
If you have thick hair these rule don't apply at all.
In general I think having dark brown hair will make it look thicker, infact it may backfire completely.
HOWEVER although people say dying your hair is bad for you it may be worth dying it a colour very close to what your natural hair is or a colour that appeals to your skin tone. Dying your hair has been prooved to thicken it, so does blow drying it as it opens the pours. Try adding curls to it for more volume.
OR if you want straight hair with volume heres a few steps to give you BIG, STRAIGHT hair* :)
step one: Get layers cut into it
step two: wash it without using conditioner
step three: hang your hair upside down and blowdry it from there.
step four: once it is nearly dry spray texturising spray(salt water works) or simply volumising hair spray or mist over it all and carrying on blow drying upside down.
step five: If you want sleek hair brush through it, If you want to go for a beachy look leave it how it is and brush any tangles out.
*this probably wont work if you have curls, if you have curls, dry it first then straighten it then blow dry it upside down. But if you have curls you probably dont need to volumise it anyway