Import the pdf into CorelDraw. If it loks the same as it does when you open it in acrobat, then it's just a matter of printing separations.
If it doesn't then you'll have to use Indesign to separate it.
Are you sending seps to a printer? They should be able to separate it for you from PDF. Are you ripping it to your own imagesetter? Then print seps from Corel. Do you need to send separated files to a printer? Print to PRN from Corel.
There are a dozen variables we'd need to know to really help. What are your requirements in the end? Files? Negs?
If you take a photo of a red apple, the image will be red. If you take a photo of a grey apple, throw it away because it's spoiled. If you take a photo of both a red and grey apple at night, the image...