Now that they are old enough, my scars are white instead of purple. I have just learned to not care anymore. All throughout middle school, and freshman year of high school I wore only long sleeves. Then I just got tired of wearing sweatshirts in July an wore whatever I wanted. I relapsed several times over the coming years, until I was 19 or 20 so I got new scars. I would cover them until they turned white-ish and then just let it all hang out again.
I find that it really isn't that big of a deal. Many people never notice because of the way I hold my arm, or don't notice for a long time, or just don't say anything. If they do ask I just say "Eh, I dunno" and don't explain further. I've just learned to accept that my body is scarred, and if I can live with it, so can everyone else.