Gun Carriage colour French

I know next to nothing about pre-eighteenth-century French naval history, but my guess is that there was no consistency in such things in the early seventeenth century. I have the general impression that European navies in general had adopted red for inboard works by the end of the century. But I'm not knowledgeable enough to be more certain.

Red is a pretty good guess.  BTW, red was used more for its cheapness and toughness rather than to cover blood.  There were several good reds, including red oxide, in use for centuries.

 As far as what color a French gun carriage would be in a 17th century ship?  It is hard to say, based on how much expense the captain would want to put into paint, the carriages would most likely be natural wood, red, or whatever color he chose to paint his deck furnishings.  Ships before the revolution were usually commanded by members of nobility, so the rails, wales, and fixtures could be whatever color the captain, or admiral if it was a flagship, chose to identify his line of nobility as well as to show his allegiance to the king.