As per the title, Which shades of grey is in these pictures?
I know that the other colour is black, but It's the shade of grey I need to know.

Image one	Image Two	Image Three
Image Four

It'll be easier and quicker if you use an RGB color picker utility either online or installed on your computer to find out from the images you have. But the varied lighting and shading makes it nearly impossible to say exactly what it is...

Grey is strictly monochromatic, so really has levels, not shades.
A 'shade' suggests a colour, so no longer grey.
(A 'shade' cannot be grey.)

Steve