I think that Othello's susceptibility to 'murderous passion' was figured as property of the dark-skinned. Hasn't the color-coded dichotomy of passion and reason been one of the oldest ideological resources used to invent races?
Speaking of the periodization, by 1600, the exploration of the 'new world' had already begun, primitive accumulation had begun (for example, seen in More's fictional comments on 'enclosure' in _Utopia_), England was on its way to the world domination, the nationalist ideology was in its formative stage, and the ideology of coloniaism with its need for racism was in its making as well. The nature of racism has changed since then, but race was certainly already being made.
This is a very interesting and important history to investigate, and when we do so, we can see the simultaneous and mutually reinforcing emergence of ideologies + social relations that have made class, race, nation, Europe, and so on.
Yoshie