Hi there,
I have a different take on this, and I'll be honest and say I was alarmed by your message. I'm going to be brief, because I tend to be too wordy onhere, which is interesting because in real life I am not verbose, but hey ho.
I'll say first, please do not take offence. I hardly ever tell people what they should do, but I am thinking about your situation in terms of need, so I will use that work a few times I expect. Also, this is a racist world and none of us is free from bias, including me.
so:
1 - Books are just a small fragment of what your little one is lacking right now. You need to think less about books and more about your lifestyle. You say you have few black friends - how has this come about? You say your partner has few black friends - how did this come about?
2 - This might not be your partner, but I know quite a few (white) people who actually do not like black people that much, they love their partners, and on some level think they are an exception etc etc. I know mixed race women who are pretty certain their mothers wholly dislike black women, including them on some level. Likewise, thinking about yourself - what are his feelings about black people? I want you to think about what could be happening why your son has so few black people (and mixed race?) in his life. These factors likely need addressing quickly. Bottom line, if I am wondering whether you and your partner like black people (and value them in your life), your son will be soon, too. I'm not reaching here. And you do not want him to come to a damaging conclusion.
3 - You say you do not live around black people, his school/nursery is v white etc. This is no good. As part of a lifestyle audit, you need to consider changing this - where you live, schools and getting black friends and engaging in black groups etc. You might very well think this is all little too much, you just want to buy some books, but I would urge you to read the other threads in this section about black mothers doing exactly this and see what they are thinking. They aren'r representative of all black mothers by any means, but it gives you insight that you might lack given you're not around black folks so much. These are things we are fully aware that we need to do, and sacrifice and compromise a lot to do, because your son's psychological and emotional wellbeing depends on it, let alone his betterment.
4- You say you have not considered these things before. This is also no good. What are the reasons for this and is it factually true? This likely requires some full frank and open conversations with your partner about race, what it means in your relationship and family and life. If you both come up with 'it doesn't matter' you are probably not being curious enough, or for some reason you are avoiding engagement in the issue. This will be to the detriment of your son.
5 - Does your son really know his skin is beautiful? How does that sit with him wanting white skin? Those seem incongruous to me.
6 - Please don't 'guess' anymore. Think very thoroughly and deeply about what is going on for your child. He's young, anything that is going on can be reversed if you act on it. You need to do so now.
Good luck.
(that really wasn't concise - ugh)