The Red Blood Cells are the carriers of Hemoglobin and therefore they are always having Red Color. At the time of fever, the hemoglobin level remains the same but the white cells in the blood count get reduced. So, the color of Blood starts becoming pale. The same impacts on the hemoglobin carrier of Red Blood Cells and therefore it could be said that while having the fever, the color will look like Pale Red or Slight Yellowish as per the fever level.
