OK people - knock it off. Everyone has different styles and tastes, if this terrazo isn't yours, doesn't mean it isn't OP's. Being nasty just reflects on you. And may I remind you, that this particular floor is a work in process? You do not know what it will look like until it's fully uncovered and properly cleaned.
OP - I also know the feeling of pulling up a floor, not knowing what's under it. Sometimes you win, sometimes you lose. I have no experience with terrazo, but good luck!