I got some purple ones on my very fair skin (read: you could see these things from fifty paces!) waaaaay back when I first got a desk job and gained a lot of weight. I dropped a bunch of weight and they went from being big purple furrows to little shiny "racing stripes." They have never been as prominent since, even throughout a fair amount of weight fluctuation.
I haven't done anything to get rid of or minimize them, but I've read that dry-brushing of the skin can help stimulate cell regrowth and improve the superficial appearance of scars or stretch marks. I'm dubious that it'll actually do much for the marks themselves, but it probably does improve the overall texture of skin as any exfoliation process would--and having tried it recently, it does feel kinda nice.
Couldn't hurt, right?