To restore SOME color, can you dye your hair without stripping/bleaching it first?

My hair is still mostly blond—it was just starting to go brown or what is called “mousy” on females—some years back, when white and grey started dominating, due to age.

I am going through the interviewing/vetting process for an associate Professor position —so I do not want to look pure blond as would come with dying my hair a solid color. But I am wanting some of the blond from a bottle to adhere. I dyed my hair successfully in the past when I was going brown but I do not want to look as blond as I did then, The only way I know to do this is not to dye it or strip the original color.

Yes, I know I am a little vain. But I want to fit in with young adults at the local arts community and coffee houses as I did fifteen or so years ago—while keeping some semblance of maturity.