I would use the lighter color Cendre. You need to picture the niche with shampoo bottles and other stuff in it, and see what you like better. I think that extending the lightness is the way to go. Once you have bottles there, the darker color will just add to the look of "clutter,"

I would go with the lighter. The dark one would draw your eye to the niche & it's not the prettiest thing in the shower with shampoo in it.

Cendre.

Thank you all - you confirmed my choice. Hubby threw me into confusion with his suggestion to use the darker color.