First, let's lay out more groundwork for this. Are you talking about racists who tell stupid jokes or Klansmen? Because I'm talking about the latter (and I realize that they probably aren't a big feature in Seattle, but in Mississippi, they show up at least once a year to march somewhere). I simply find it disgusting to appeal to them.
And to my knowledge, the "they're not mean, just ignorant" is a myth. Some people simply hate black people, or Muslims, or LGBT people, etc... and they state that if asked in the company of white hetero folks. My own father-in-law is a Trump supporter who says his favorite song is "White Christmas" *wink wink*. These people exist; they're not dumb, and the real world isn't a Disney channel original movie where people are swayed once they see the real truth (or whatever).
I really don't know how you can look at something like that other thread in OT right now (with the TN guy putting up billboards that say "I Have a Dream" with Confederate flags or "Make America White Again") and say, "That guy's probably just not as knowledgeable about people of color. Shame on you for not appealing to him!"
See above for changing people. People that tell racist jokes? Maybe you could get through. But I think there's a sizable portion of our nation that simply doesn't like people of color or any other minorities, and you won't change them with a hug or a TV show.