JDF,
The way that I read the verse you cited, Luke 6:45, is not about outward appearance that come from the outside.
"The good man brings good things out of the good stored up in his heart, and the evil man brings evil things out of the evil stored up in his heart. For out of the overflow of his heart his mouth speaks."
This is referring one's speech. The words the come from inside you....the flow from the heart to the mouth to the outside world....is either good or evil.
This isn't about things from the outside coming to you, such as clothes, make-up, slogans on tee shirts, length of one's hair.
I, for one, don't care for tattoos myself. But unless a person has a tattoo of Satan, or demons, or naked people on his or her body, I try very hard not to make judgments about their salvation, their worth to the Lord, or how many sexual partners they have.
I've come to learn that the heart is deceptively wicked and many, many people out there who give the outward impression of being saintly are anything but that. And unfortunately, I have learned it the hard and painful way.