I dye my hair either brown or a reddy brown I'm 46 I would like to no if giong black would age my face

Going black will not make your face look older. But, if you have fair skin, the black hair color may make you look washed out or pale.

I am the same age as you and have dyed my hair very dark purple over dark red and it is almost black. I must say it makes me look washed out and pale without heaps of make up on. I have been thinking of going back blonde as my roots are pure white and need touching up every fortnight. If I were you I wouldn't go black.