Blue will make the hearth jump out....is that really what you want?

i'd want it to be a good contrast to prevent tripping. i hate those semi raised hearths when they are anywhere near walking paths!

Paint it black.

Hi nnigrt! I agree with leelee. Paint the hearth white to match the surround, then see what you think. I think you'll see that there is enough contrast between the white bricks and the grey floor to ensure that there's no tripping hazard. If you're thinking of cozying up that area of the room with an area rug and a couple of chairs, keep that in mind also. Making the hearth stand out could fight with any rugs you'd like to use nearby.