Does colorfix lighten hair color?

Like, bleaching is out of the question, so when I take the color out will it lighten it some because after I plan to use a high resolution golden brown dye mixed with a neutral brown dye so instead of bleaching it, would that lighten it?

Does Colorfix work on semipermanent dye?  I started life with medium brown hair, dyed it a very dark brown with semipermanent dye for years, and now want to go to medium golden brown permanent dye.  Semipermanent dye is actually incredibly tenacious.  I've been washing it out for four months, using Prell as often as I can without drying out my hair, and volume conditioner which is supposed to expand the hair shaft and help release dye. I now have ombre hair--my natural color (now mixed with gray) for the first third, a darker slightly reddish brown for the middle third, and a brown only slighter lighter than the dark dye on the last third.  Looks awful, it's a good thing I work at home.  Will Colorfix get rid of the rest of the dye without frying my hair (which is very fine and mid-back length)?

Thanks,

Fran