normal but id try
black oil interior satin trim paint, id guess knowing the tile, brush
and rag off the excess mess, but it will take days. You need it
real clean first. But black is probably to black, get a deep bronzetone
and mix into black a slightly lighter color.
Do you really think that the paint will adhere to the "fake
grout" -- if I were to add something black to the "grout", I was
thinking more in terms of some sort of permanent ink or stain.
However, if paint would actually work that would be great.