OK. Now that I've stopped panicking on your behalf, I see what Xosni was aiming at.(posted 8511 days ago)
You could try a re-halogenising bleach bath, followed by re-development in C41.
The trouble is that most C41 kits use a combined bleach-fix bath these days, and this WILL remove the image in its entirety, as will a hypo-ferricyanide bleach.If you can find an E-6 or C41 kit with a separate bleach only bath, then this might enable you to get some sort of colour image back. I still think it's safer to stick with the B&W negs you've got, and try to remove the brown dye.