These are amazing stones! To summarize, the round diamond cut has less saturation than the cushion. It's a tad brighter, but less blue. If you tilt it slightly, the blue color goes a bit grey along the crown. You can see it a bit in the pictures, but much moreso in person. I don't think one would notice unless comparing the two stones; however, when I looked at them separately, I did notice one was more blue. I tend to prefer cushions, so I'm pleased that it has the greater saturation. Edited to add: when I turn the stones upside down, the color is identical. The cut makes a big difference. Interesting! See the last two pictures for what I mean. When I put one on my hand at a time, I really like both.
The color is gorgeous, gorgeous, gorgeous!!! Did I say gorgeous!!! The camera takes away the violet undertones it has, which is too bad. You MUST see this in person to appreciate!
They don't black out; they always show blue. The faceting doesn't show if there is absolutely no light. If it's daytime and I'm just sitting inside in a random, not bright room, it still shows good faceting.
And since we know this thread is worthless without pics, here ya go. All picture taken outside in the shade.