It will get black, don't worry.
But heed the above advice of never using soap of bristle pads. let the oil build up.
AND... know your "smoke points" which is the temp at which oil burns. Use oils/fats that can tolerate a lot of heat: Walnut, Canola, Sunflower, Sesame as examples - stay away from cooking with Olive Oil... tastest great in a salad or at LOW temp but it burns easy.