How to repair worn gray grout on my kitchen counter?

Rar29251210
by Rar29251210
I have off white/beige 12" inch tile on my counters with med. gray grout. It covers all counters and goes up the walls. very attractive. But, after 15 years, near the sink/stove area, the gray grout has turned darker and is worn now to the backing board in some places. How do I fix this inexpensively, but get it to match.

  2 answers