Maybe, in the case of football, if you don't want to take the knee (which is fine, is your right and does not make you a racist), you just need to stand in silence to show your solidarity with the message.
Rather than booing the players who make the gesture.
And, looking at it another way. A lot of people are saying it's enough now. Time to stop the knee gesture. But if that gesture was, say, standing up for disabled rights, or even something simple like 'we believe the BBC shouldn't be charging pensioners for a TV licence', I doubt there would be any boos even if they did it for years. It that's the case then those who do boo it, who do think it needs to stop, need to ask themselves why.
So, in answer to the question. As a white person I have absolutely no problem with people taking the knee. I don't (and won't) do it because I see it as subservient when I think all people should hold their heads high. But I will stand silently supporting anyone in your right to do it and, should remarks/boos or anything else be made, I'll make it very clear where I stand.