Help - model paint on slate floor

[Theduchessstill]

As the title says, ds13 spilt paint for painting models onto the slate floor (I don't think it's actually slate but a very good imitation, if that makes a difference) while I was out shopping. Instead of mopping it up he rang me and, when I told him to "wipe it up then ffs- " he did so badly. By the time I got back he'd just smeared it around and it had dried. Now it won't shift with white spirit and is quite unsightly. Any ideas?

Methylated spirits will dissolve the paint, had the same issue, very smelly but effective

Rubbing alcohol got black grafitti off the grey box (the one full of telephone wires and stuff) outside our old house.
Try a small patch first, whatever you use.