Sandblasting will lighten the color. They are heat treated steel and have a medium gray color. Try paint stripper. I coated mine with Eastwood Diamond semi-gloss clear with cosmoline over that. Cosmoline is available from Rick's in a spray can. I keep it on all the black oxide bolts.
Unfortunately, I did not have many other alternatives after they painted them. I agree that sandblasting does lighten them up, but they guy did as light of a job as he could.
I have used Eastwood's clear in the past and have liked it too. I guess I will have to remove the Boeshield or wait for it to come off before I paint the springs with clear? Can I put the Cosmoline over the Boeshield?