The 5m and 8m are a blue colour that blends into the ocean color as you get further away. Brighter colours would be ideal.
Yesterday the wind was gusty, with some big lulls, and I was on my 4m peak. I retrieved several boards for people who had dropped their kites. One was using a closed cell that had bowtied. Another was using an inflatable, and they couldn't get it to relaunch. The inflatable was being pulled out to sea with the tide, and it he had a long and tiring swim, hauling a big draggy kite. My peak 4m never threatened to fall into the water.
One of the skills that's useful for hydrofoiling is an awareness of where the kite is in the sky, and this includes while you're crashing. If you have good kite awareness, then you're not going to steer a peak into the water very often, and it has to be extremely light wind before it will fall out of the sky. How well the kite relaunches becomes much less important in this scenario. As with any type of kite, things can go wrong, the wind can drop, you might not be able to relaunch and you should be able to swim your gear in.