I got this plant about 3 months ago, so I can't really take credit for the flowers. Took it out of the pot and mounted it, it's been growing new roots for a while now. The flowers are a bit less than 2" wide. I was aware that if this plant is shipped in bloom, the flowers will turn pink then go back to violet-indigo after it's back in the light for a few hours. I wasn't aware that the color varies by time of day as well. First 3 photos were taken around 1:30 PM. The last photo was taken about 7 hours later. It's not temperature or light doing it. We've had some mostly abnormally cool weather this May along with a day or two way above normal. Didn't make any difference in the color change. The flowers start going from indigo to violet after 2 PM (starting in the central vein of the flower) and by 6 or 7 are pretty much violet. In the morning the color change seems to start before the lights go on at 8 AM and is back to indigo by around 10 AM. Intermediate, let it dry out a little in winter, will be keeping it quite moist in summer. Growing in bright shade.