When I built my Revell 1/72 scale Schnellboat, I used a Dark Grey ( Testor's gunmetal grey )
Can't remember where I found the Information /reference for the color, but it was out there somewhere.
This model was built by Don Jamieson, but he used the same color I did for his liferaft.
( Or, at least a very similar color. His may be a Anthricsite Grey over Black. )
On this model they are the same color as the deck.
These appear to be Anthricsite grey.
This model was built by P.A. Boillat
Bronco model's would have you paint them like this.
And, I found a "Color" photo of some.
BUT: I have also seen them painted Tan / orange ... And I have seen color photo's of some that were Yellow.
I'm not sure which way is right. ( It's possable they all are.)