Hi Jamie,
As you say, a bit deck chairy!
Bearing in mind the flooring timber would all be the same species, the colour would not vary very much, particularly if it is one of the normal softwoods, although there are some surprises: the colour variation would be within the board itself, not really from board to board, and normally very subtle.
I have an original tender specification for GNR wagons from The Engineer 1882, which states the boards should be "best St. Petersburg deals", and only the outside of the wagon to be painted. The framing to be of St Clair white oak, which is usually pink in colour - it is the flowers that are white!
From this I would suggest that the newly-sawn colour would be light buff, almost white. Have you used Jelutong for the floor? If so, I'd use that as the basic colour and then whether it to look like it has been outside for a few years. To me it all looks a bit too brown (apart from the red board), and also too strong a colour, whereas I'd suggest more grey, and keep it light.
I don't want this to sound too critical (please don't say, "Well, let's see the one you've built!"), but next time try using a species without the dark flecks in the grain: lime or sycamore would be good if you can get it. As you might guess, I've spent many years staining and french-polishing wood!
Best wishes,
Susie