Thanks folks.
Just wanted to confirm that the colour of my interior is in fact Orion Grey.
Here's the codes under the hood. I'm fairly sure it is but thought I should probably ask one of the folks here who knows for sure!
I've been looking at the above sources and also here
https://leatherworldtech.com/mercedes-leather-dye-color-chart/
Strangely, there seems to be two Orion Grey options on the above link (M140 and 7313), but my option code is 268 - which isn't on that site at all..!
Thanks!