Flagstones in kitchen

[Daljit]

Dear All

Flat (c1790), Edinburgh, has dark grey flagstones in the kitchen. A few are worn/chipped and the gaps between these is big enough for debris to gather. Can someone tell me what i should use as filler?

cheers

Daljit

[Grunff]

Grout, choose a colour that complements the colour of the stone.