We would take into account their ethnicity, culture, learn their native language (if appropriate), possible religion, and we would mould ourselves to them, rather than the other way around.
I can understand your thinking here however, there are challenges in interracial adoption which have been outlined well by posters with that experience.
In any event there are things you can’t mould yourself to in all adoption. My children have had experiences that I haven’t, there are things about them that I can seek to understand and that can inform my care of them but I’m me and they are their own person. For me to mould myself to them would be unfair and inappropriate in a single race adoption, never mind an interracial one.
You will never experience racism and discrimination in the way that they will, as a white male you won’t experience structural inequality in the way that a black child will - you can’t mould yourself to that part of your child.
You may want to be very open about adoption at the start of your journey, that may well change as the process is pretty exposing and I know for me at least there was a point I just wanted to live our life as a family. Adoption is openly spoken about in our family and our children are proud of being adopted (that may change too), but it is their personal story, not mine. A child may not want the question of heritage and adoption to come up every time someone new meets their parents, to be the poster child for mixed race families etc etc. By actively only considering a black child you remove their choice in favour of your own.
You can be happy to make adoption your first choice, for any children to know they weren’t “plan b” without the very obvious marker of skin colour. There’s no awkwardness when people talk about my children looking like me or having my mannerisms, they’re my children I dearly hope there are family resemblances developing.
If your desire is to care for, love and nurture a child, to help them reach their potential, you have a lot to offer any child, you need to carefully consider why you think you could only offer that to a black child though because what you’ve said about the reasons for wanting an interracial adoption would raise questions with any social worker worth their salt.