Most people will opt for either a crisp white grout O1 for a fresh traditional feel.
Or go grey 09 if they want the interior to look slightly more nostalgic or to have a more industrial vibe.
If however you would rather use a coloured grout to create a softly textured surface , consider Colour 18 Sage.
Recommended Grout Joints - (We have assumed that your substrate has a perfectly flat and plumb surface, please check with your tiler).
4mm grout joint. Based on this joint size, 1 bag of grout would cover 2.4m².