Having toured the Dreamliner a couple of times in the past, I already knew about the new windows. Not only are the windows much bigger, but they don’t have shades. Instead, there’s a control under each window to adjust the amount of light allowed through.
I had tested this feature before and was impressed. However, I never sat there and watched it dim fully. I’m guessing it takes about 30 seconds to a minute to go fully dark. Here’s a pic after about 10 seconds with an undimmed window beside it:
Once the window dims, it is very dark blue in color. Perfectly fine for sleeping, yet the person in the aisle can still see through the window. I got some great shots along the way. Here’s a quick view of the wing through the fully dimmed window: