Grout yes/no + color help

Ok so this whale fin (picture 1) was the first mosaic I've ever made - obviously, I had a lot to learn during the process. I was too scared to grout the mosaic as I thought the details and strong blue fin-colors would be lost if I did - I was just not convinced to grout it😅 and somehow to just leave it as it is wasn't an option for people I talked to. I added picture 2 as a close up to show the gaps better.

Past forward a year and I'm doing my second ever mosaic (picture 3) - it's gonna be a present. I was SO sure to grout it this time... and now I'm not sure anymore. I just feel like the marble shines more through like this. What do you guys say? And if grouting, what color would you use?

Thank you for your insights!!