I believe in letting potential employers know my skin colour as soon as possible to avoid problems further down the line.

I do the opposite, to let them have as many problems as possible with me if they are racist employers!
You won't stop racism by being compliant to those employers who aren't racist.
Take on those who are. Change doesn't come by waiting for it to happen nor by ducking out of challenging racists. Give them big headaches. We should be proud to be black, and they ashamed to be racist. Let's make them feel so!