How much to replace brake calipers and lines on a '98 mustang?

my back brake calipers are getting really rusty and i dont want them to start to seize up but the discs look fine so i am thinking of just replacing the calipers and i would like to get the coloured ones. how much for purchase and installation on just back calipers and on front and back calipers? would it take long? and how much would it cost to install new brake lines? is this a big job?