From Wikipedia:
Othello's race
Although the play is very much concerned with racial difference, the protagonist's specific race is not clearly indicated by Shakespeare. Othello is referred to as a "Moor"; for Elizabethan Englishmen, this term could refer to the Arabs of North Africa, or to the people we would now call "black" (that is, people of sub-Saharan African descent). In his other plays, Shakespeare had previously depicted an Arabic Moor (in The Merchant of Venice) and a black Moor (in Titus Andronicus). In Othello, however, the references to the character's physical features do not settle the question of which race Shakespeare envisaged (Othello's line "Haply for I am black" does not help, since 'black' could simply mean 'swarthy' for Elizabethans). Popular consensus among average readers and theatre directors today leans towards the "black" interpretation, and Arabic Othellos have been rare.
But they were darker than the average Briton, leading to the term "black." You'll find similar references to darker-skinned folks throughout northern Europe.
If by "not black" you mean they didn't have curly hair, thick lips and flat noses, probably right.
But the skin of Northern Africans can be extremely dark. There is quite a variation in skin color in North Africa. They sure aren't Caucasians.