Thanks for writing to us.
Few lasers like q switched laser or IPL show good results in becker's nevus
. However a number of sessions might be required.
If its a small nevi and that too in covered area of body, it is better to leave it as such. How would tattooing the area enhance its beauty. If you get bored with the tattoo again you might have to get lasers done.
Chances of a Becker nevus turning malignant is almost negligible. However I would not advise tattoing the area as you said no change that may occur in nevi( even if its highly unlikely) can be seen.