Ultimately, it comes down to your imagination. What kind of wood do you want to achieve. Check google images for samples and ideas. Pick the colours to match your game. Not always do realist colours work best. Sometimes it’s about the texture more than the colour. E.g. a red door can still have a wood texture to give it character.
Play around with the technique and enjoy creating vector art!
Get the source art
(svg file) (not including the art files of the pirate sample) of this tutorial for free.