As mentioned earlier it's been difficult to find any colour information on the Mauretania's Smoking Room. Searching on-line I've found only three types of interior colour images; hand tinted magic lantern slides, commissioned watercolours for brochures and cigarette card illustrations.
In 1913, Joe Goodwin and Lew Brown published "He's on a boat that sailed last Wednesday" with a cover sheet using some of the tinted images. It shows the Smoking Room in garish colours, as the only coloured image I'm happy to have found it. Shown below is the tinted image over the plate glass image (hover to reveal). The colour was either added by hand to the back of the plate, for use in magic lanterns, or added during the printing process.
Tyne and Wear Archives ref: DS.SWH.18.104.22.168.B358
I'm pleased to see my choice of colour for the soft furnishings is similar but I doubt the carpet was entirely red. Looking at the plate the carpet shading determines a number of colours were used. In addition the ship particulars note 3 different types of carpet -
180 yards of 3/4 Body Carpet, 55 Yards of 10 1/2 inch Border, 94 Yards of 7 1/2 inch Border.
To the left is a croped area of carpet I've skewed to provide an overhead angle, next the material map I've created in Photoshop. The colours I've selected are from an Edwardian colour palette and fit with the shading information on the original plate. Below is the result rendered with texture and shading.
With these final elements in place I can now complete the model....