I dyed the underneath of my dirty blonde hair... black! It looks really good, but the black is kind of bold around my face and sideburn area... Is there anything I can do or use to soften it up a bit??

If your hair is blonde and you use a black hair color under your hair, it will make you look washed out. A brown or caramel color would look better. If you shampoo your hair frequently with warm water, it will fade the color slightly.