Need to change grout colour

[Roger Dygas]

I have laid 30m2 of light grey 300x600 porcelain tiles, and the grout is too light (same colour as tile). Is there any product out there I can use to darken/stain it a dark grey?

 

[Boggs]

Mapei Fuga Fresca

 

[Stu Lilley]

Mapei fuga Fresca is a poly modified paint... easy to do and many colours to choose from