If you're exhausted and unwell, your skin very likely has a quality of pallidness, or lack of healthy color. One look at the pallidness of your face, and your teacher will send you to the school nurse.
The noun pallidness means "having the quality of being pallid," or very pale. In fact the Latin root, pallere, means "be pale." You can use this word or its more common synonym, pallor, when you're describing someone who's so pale that they seem to be unwell or in shock: "His pallidness was soon explained when he described the ghost he'd just seen."