It is true any discussion of the subject marks you as a racist so how can we have an honest conversation in such environment? Just look at your own down votes?

Having said that, even if the academic outcomes of people with darker skin color were worse (no idea if that is true, or in which country) just knowing that is no proof. It may as well be cultural or even income based (pregnant mothers eating worse quality food for example, or same thing with young children).

Is the question even answerable? What kind of intelligence do we measure with "academic outcomes"? How do we adjust for income and quality of life as a child, things like having both parents, or grandparents? It's an absolute minefield of possible manipulation. Same data can probably be spun to "proove" any hypothesis you have.

Then imagine writing a proposal for such research. What benefits can you predict? If you find there is absolutely no correlation between skin color and academic outcomes after adjusting for all external factors will it convince people that are racist as part of their identity? I doubt it.

Lets say you do prove there is some correlation. What the result of that would be? Open discrimination and vindication of racist views. But even if the principle was true the average doesn't apply to individuals so you can't apply it to any particular person.

What plausible mechanism is there to even approach the idea that skin color influences intelligence? Why not study the effects on intelligence of eye color, or blood type?

This is especially clearly just a racist concept once you realize that none of the studies of IQ vs race actually do any genetic testing, they only rely on phenotype. Which is absurd given the fact that the child of a black-skinned person born in sub-Saharan Africa and a white-skinned person born in a village in Ireland is extremely likely to be black-skinned, but is genetically just as much part of both populations. It's only the history of racism that assigns this child as black more so than white.