Hi,
soory for commenting so late ...
On the picture with 3 funnels, pre-war mast and gun spaces she sports overall dark grey, likely "home fleet grey" (507A), and flies the White Ensign. That means at the time the picture was tanken, she was an AMC. The use of 507A as an overall colour coat is limited to the very early phase of the war.
I think, the pictures with 2 funnels and civil colours have been taken after the war (see also the civil passengers). Troopship in the late war never sported civil colours but were usually painted all grey (often the so-called Merchant Ship Side (Dark or Light) Grey). Just search for pictures of QM and QE. Also, troopship had only very few boat but a huge number of floats.
Cheers
P.S.: Jeff is absolutely right
