Grouting between Indian Stone Paving

[Iestyn]

The latest frost has ruined some grouting re-done lasgt September. The builder obviously used the wrong mix as the grouting ( what's left of it!) is still 'pink' and not grey like the remainder. What mix should I use to replace the latest grouting? The original, which is grey-cement coloured, has been there for ten years and is OK. I want to match the colour as closely as possible.

[welsh brickie]

the grouting could be quite hard to match but try 4:1 mix sharp sand and cement.Keep it dry with very little water so you can brush it in the joints