Is black semi-permanent hair dye hard to remove?

I know that it’s semi-permanent and can wash out (duh), but is it hard to remove completely? I have purple in my hair and I have to dye it to a more natural hair color for my new job. I don’t want to get rid of my purple altogether, and because this is only a summer job, I thought semi-permanent dye would be a better option.

If I use it to cover up my purple, will it completely wash out eventually, or will I have to rebleach it? I am only asking because I used to have blue before and it wouldn’t come off all the way, so I had to use hair bleach.