No problems seeing the kids at the bottom of our Midnight Blue pool. We actually added Black Onyx to the Midnight Blue Mix to make it even darker which is what we wanted. Here's a link to our pool. The color varies widely throughout the day depending on the suns position in the sky. Directly overhead, the pool is a bright blue while at sunset or sunrise, the pool takes a darker blue color. Hope this helps. Here is a link that might be useful: Pictures of Midnight Blue

My brand new liner is called Midnight Blue Glimmerglass. I love it! I don't think it's too dark. This was taken after the sun was half off of it.

Great choice on deck and coping , as what I can see I would lean towards the classic, unless your heart is set on the brighter blue. Think daytime and evening with nice lighting. Let me know if your keeping your top step or demo. Cheers & Goodluck

Dark finishes tend to have the possibility of "mottling", a variation of color when finished. We tend to use the grays and alike as they are neutral, have good finishing properties and essentially match with most tile and coping colors. Photographs of finishes are tough to capture the real look. Every pool has a slightly different setting so sun light and shade create a unique cast. Visiting completed jobs is the best way to see results. In the beginning of the day and the end to see changes. Sample chips are available from manufacturers. Even with a 2"x2" chip, the sample is a good representation. Wetting the sample further helps. Taking the sample outside where the pool is/to be, allows the natural light to show it's color.