How Can I Fade The Color Of My Scars?

I have a lot of scars on my arm from a stupid period of time in my life about nine months ago when I would cut. I'm embarrassed about it, though, because the scars still haven't turned silver. They stay a dull pink color, but often turn dark red when I'm hot or bright purple when I'm cold. None of the adults in my family know, but I know they're noticeable because several of my nieces and nephews have asked how I got them. I really, REALLY don't want to have to explain them to anyone, so does anyone know how long it takes for scars to turn silver? Or is there anything I can do to hide them or minimize their color? It's far too hot for me to wear long-sleeved shirts now, and makeup foundation doesn't cover them well enough.