This is a somewhat thoughtful consideration of the topic--at least you attempt an argument of some length--but it deserves a robust counterargument and rebuke.

(1) You claim to have conducted a "real research to quantify exactly how the two colors performed over history". And do you share this research with us? No. Do you share not the basic research but the quantitative conclusions? No. So we are left with this entire endeavor needing to be taken on the basis of your authority. Not very compelling!

(2) Your inattention to bits of history that are inconvenient for your hypothesis (i.e. most of history) is rather astounding. For example, the kind-of-slightly-brownish Greeks produced a breathtaking series of intellectual advancements with a tiny population in a minuscule portion of the world--and when their closely-related neighbors, the Romans, took over, it came to a screeching halt. The things that the Romans made advancements in (mostly building and politics) were things that many human cultures have made considerable progress in, and which don't really require the inquisitiveness that you seem to prize most highly. Then, when the even more light-skinned northerners exerted their dominance, we had a lovely period of several hundred years of abject backwardness and incuriosity even relative to the Roman standard. Indeed, science was always there to find; we just didn't do it, any of us humans, of any skin color or geographical origin, for a really, really, really long time. If the Greeks (Athenians especially) had been able to defend their territory for a couple hundred years longer, there's a decent chance that the scientific revolution, and the science-enabled industrialization that gave western Europe world-conquering power, would have come from Athens instead. The point is that it's so capriciously fickle that if you want to make any robust conclusions, we need to see all that evidence you claimed you had but didn't show. If you want to cherry-pick evidence for exactly the opposite point--that light-skinned people are the most destructively incurious bunch around--then it's not hard to tell that story either, ranging from the Greenland settlers who wouldn't adopt local customs and so died when the climate grew colder, to the obliteration of the Incas with scant documentation of what they were destroying, much less trying to learn from it. There is a lot of history to pick from. You can tell almost any story you want. Especially if you allow yourself to wave your hands and speculate that advances of unknown origin that could maybe possibly if we don't look too closely could have come from an influx of light-skinned people were, of course, exactly that, and those correspond to all the important advances.

(3) The inference that, even if everything you say about cultural patterns is true and complete (it isn't!), therefore it's genetic rather than cultural, is unfounded. Firstly, it's difficult to entangle these things: Jewish culture has managed to survive in several offshoots for an incredibly long time, for instance, so you can't conclude that just because it lasted, it's genetic rather than cultural. Secondly, in melting-pot countries like the United States, people have actually asked the question whether race (as typically classified), as opposed to cultural factors, can explain IQ. Our best answers--where we really try to dissect the cultural factors rather than assuming they're unimportant--are "either no, or at most a tiny effect" (LeWinn et al., 2020: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7506587. The race covariate has a confidence interval of -0.14 to 2.26--see eTable 3 in the supplementary, and note that this tiny IQ score range consistent with their data encapsulates not only all genetic differences but also the total impact of racism that isn't already reflected in the other metrics!)

So if you have some good reason to believe what you say you believe, you need to raise the quality of evidence that you present tremendously. Otherwise, the diligent student of history and social science should disregard your claims as at odds with far more reliable evidence than you have presented.