Wood decks can drive you nuts. The Navy used to scrub the decks with mix of bleach and pumice,
so the wood was very light. Teak weathers out to a light grey with a touch of brown/tan to it but turns quite dark when wet.
The best results I've had are a mix of Tamiya deck tan and Sky grey, then a sludge wash of any dark colour, Flory washes work quite well.
It depends how nicely the planks are moulded so you need to persevere with the wash to leave just the seams picked out.
I'm never satisfied but Seydlitz is the nearest I've got to the effect I'm after.
Haddock.