The first two photos are of the Royal Marines Light Infantry of 1914 set rather than Royal Naval Division. Differences in the jackets and caps but should be in a nice navy blue uniform with red trim. More Napoleonic than Great War but a nice change of colour.
Looking great, including the Lewis Gun Team in another post. All your figures will go well with the WDLR 4-6-0T Baldwin locomotive and wagons in 1:76 scale, that Bachmann has announced this weekend!