i've been dyeing fabrics since the mid 70's...pre-washed fabric /with detergent- without fabric softener==is PFD fabric!
truely- that's all it is--fabric that has been pre-washed to remove any sizing/chemicals.
you can dye anything you want-i've dyed lots of prints i wanted to change.
as long as it's a natural fiber (cotton, silk, wool) you can dye it and have lots of (surprising fun) doing so. {polyester/non-natural materials) do not dye well
Visit the Dharma Trading Company web site- they have lots of 'hints, tips, advice along with lots of supplies- a good resource- i've actually been shopping with them for 20+ years
2 great (resource) dye books i've had for years and turn to on a regular basis are:
Fabric to Dye For and
The Fabric Dyer's Dictionary
they will give you (recipies) for creating 70+ colors with 6 colors of dye
and 12-14 step gradations
along with lots of other techniques, helps to get you started on your dyeing journey.
i've been including at least a piece of hand dyed fabric in every quilt i make for many many years- i love creating my own fabrics- and have made some great backings for some spectacular quilts-
i buy alot of 108" wide cotton flannel from Fabric.com and then dye it how ever i want for quilt backs. (i've done lots of regular cotton s too- but i love flannel backed quilts- i've dyed lots of wools and silks too.