Do you remember the exact colour of something you saw only once?

I spent the morning trying to match a specific red from a surgical photo the surgeon insisted on — I kept getting close but never right, and it made me wonder: how do we hold colours in memory at all? Like, I can say 'the red of a fire truck' but I couldn't mix it to save my life. Do any of you carry a colour around in your head, one you couldn't name but would spot instantly?