Sure. They might outlaw brown hair, too. They might outlaw last names with vowels. That hypothetical, imaginary risk doesn't make it sensible to dye your hair and change your name.
Tell the 6 million Jews, hundreds of thousands to million+ Romanis, and hundreds of thousands of disabled who were systematically exterminated by gassing, shootings, starvation and various other means that being outlawed is a "hypothetical risk". Even beyond WW2 to say what you said is so incredibly against any form of historical understanding that one must start to wonder what your motive with it is.
