No, always suggest a dark grey.
Reason being, when have u ever seen brown joints in a timber floor?
Every timber floor I've seen has dirt between the joints after a while. So I try to mimick that with the grey
I've always used a dark grey too but on my last job (porc wood planks in a hallway) I used Mapei's UC Mud (136) and it really suits it.
Mixes up looking like mapeis chocolate but dries a dark grey with a slight hint of brown (like dirt!) - this colour will be my first choice now if I'm asked what grout I would recommend for these tiles.