I can screw up the simplest jobs sometimes.

I regrouted our shower. I started on the floor, worked my way up the
wall. Working in the shower roughed up the new grout between the floor
tiles so at the end I put more on the floor to smooth and fill the bad
places. I really don't know if it was a bad thing to put grout on wet
grout.

Now two weeks later there are places on the floor where the grout is
still gray instead of turning white. Maybe 10% or so of the grout on
the floor. Some scattered around the floor, a few places where there
are lines of gray. All the grout feels hard, even the gray stuff.

I still haven't sealed it, hoping it will finally dry out. Has anyone
ever seen something like this happen? Am I going to have to regrout
the floor? Or, curses!, have to call someone who actually knows
something about ceramic tile.

Any suggestions or experience will be appreciated.

Thanks,
Richard