Your Silicone Colour Opinions Please - Tile Advice

[ambient]

Hi, I need to silcone a few places in my recently refitted downstairs loo but I'm unsure what colours to use and where because of the dark tiles and grout.

Photos available here...

• New item by Oliver Pearmain - https://photos.app.goo.gl/DFeBTkBmjBRfyRKT6
• New item by Oliver Pearmain - https://photos.app.goo.gl/rRwndhanaQxy5BF58

I'd very much appreciate your opinion on what colour to use for:

a) toilet back to tiles
b) toilet bottom to floor (a very light white LVT is being fitted)
c) between sink & tiles

Additionally...
d) do you think I should silcone around the toilet tiles where they meet the wall, or is the existing grout sufficient

Any input greatly appreciated

 

[STEVO]

A c and D go with something mid grey. B go white