Silver vs Grey Tabby

What is the difference between a silver vs grey tabby?

Spencer and Katie were near identical twins when I got them in January. If you looked closely, Spencer was just ever so slightly larger than Katie, and he was also ever so slightly lighter in colour than her too.

Fast forward to today. They are now 8 months old tomorrow, and he is so much more lighter than Katie is.

She seems a light grey with dark grey to black spots/stripes.

He seems more silver tone with light to dark grey spots/stripes.

I'll get some pictures and upload, but in the meantime, can someone tell me the difference between silver and grey tabbies? I've googled images for silver tabbies and some come up as silver with marbled grey/black and some come up as looking very much like Spencer.

There is no grey tabby. It's either black, blue, lilac or brown tabby. The difference between regular vs silver is that silvers have pure white undercoat. The main color of the cat (black or blue) can be figured out easiest from tip of the tail or paw pads. My Tomu is a pale black silver spotted tabby, does she look like this?