Hi @Giulia,
A warm welcome to the Bunnings Workshop community and thank you for your question.
I'd suggest giving the hole a good clean out to remove any loose material that could affect the bond of your filler.
Once clean, fill the hole with PC-11 56g White Epoxy Paste. Allow it to dry, then give it a light sand to smooth out the epoxy.
Once dry and sanded, grab some colour cards from the paint section of your local Bunnings and take them home to compare with your tiles. Pick out the closest colour that you are happy with. You can then get the team at the Paint Desk to mix you up a sample pot of the colour you've picked out.
Use a craft brush to paint the epoxy to better match the colour of the tiles.
This method will give you a quality aesthetic repair for your tile.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
