What makes a bruise turn colors?
Published July 25, 2024 | 
A bruise is a collection of blood in tissue; your description suggests that the blood is in the subcutaneous (below the skin) tissue beneath the site of the injury. The painful lump is most likely a hematoma, a localized collection of blood that is usually clotted. Such clots are slowly absorbed by the body; they pose no risk of traveling to the lung (pulmonary embolism) as they are not within a vein. If the lump persists and continues to cause discomfort, you should consult with your doctor about need for more active treatment.
The changing colors of a bruise are rather spectacular at times but only represent chemical changes in the hemoglobin of the red blood cells as it undergoes breakdown so that it can be reabsorbed into the bloodstream. The protein components as well as the iron are recycled in one of nature’s efficient and fascinating systems. Your skin should return to its normal color before long.