Bathroom floor tile grout

[princesssparklepants]

Quick q...
Had our bathroom done just over a year ago. Had tiles laid on the floor.
This is the state of the grouting. Is there an easy way to repair/make look better without removing all the grout?

You can just go over the chipped bits with some more grout and then use a grout pen to even the colour up.

An incompitent plumber I had in ruined the new grout in my downstairs toilet.
After trying to clean it with everything you can imagine it still looked bad / yellow (it was oringanly light grey )
I bought 2 grout pens in colour i wanted on amazon which has really made a big difference.