I have 3 areas to store garden stuff, depending on what it is. Our garage is out since that was taken over for a model railroad. We had a shed at our old house and quickly learned it should have been twice as big, so built a 12 x 16 shed where we are now. This is great, but fills up quickly with lawn tractor, snow blower, and other larger equipment, although I do store 5 gallon pails, garden ornaments/statues and other larger garden items in there. Then I have a much smaller utility shed where I keep most tools like shovels, spade, fork, rakes, and stakes. This has worked out so well to quickly throw larger tools in at the end of the day and it's sort of "in" the garden with easy access. Our shed is on the other side of the property so my laziness would get the best of me and tools would be laying all over the yard or in a neat pile somewhere as opposed to put away. We also recently got a potting bench that I keep on my front porch. I don't use it for potting but rather store all of my small tools in it. Pruners, loppers, zip ties, twine, small stakes, wasp spray, etc.....great easy access and the small tools never get "lost" in a smaller space so they're easy to find. While this pic was really of a garden bench we were restoring, in the background you can see the potting bench. Guess I've never taken a pic specifically of it. Before I got the potting bench I used to keep a 2x2 Rubbermaid bin in my hall closet. I'd throw in all my small tools, garden shoes, etc. The thing that helped me most with garden tool organization was having storage spaces that "fit" the tools I was storing as well as proximity in the garden, to the house, etc.

I watched the video you posted and you're right it would be over kill for a shed. Not to mention expensive. It should work very, very well (how they show in the video). But due to the expense I could almost see people (roofing contractors) modifying the process to reduce costs. This could easily be 3 times the cost of a regular roof, maybe more. So if not doing it yourself you should keep a close eye on contractors to make sure the roof is installed properly. That vent system they show in the video is a key part to making it work. It would be very tempting for a roofer to skip that part to reduce cost. Once the roof is on how would you know if the vent system was installed? So keep that in mind. Also if the metal roof is not sealed properly if the roof leaks you're talking one hell of mess to find a water leak with so many roofing layers. You definitely do not want to hire amateurs I can tell you that much. In some areas metal roofing may not be allowed due to HOA so you want to consider that too.

Unless you want to highlight the shed, white would be my last choice. I vote gray or matching the fence. We used a very dark gray on our shed since we wanted it to blend into the adjacent woods. I think we were inspired by this or a similar Houzz story on using black outside https://www.houzz.com/magazine/get-a-knack-for-black-in-the-garden-stsetivw-vs~18848563

Actually I thought about faux plants but was afraid, even with UVA protected plant products, they wouldn't hold up in the full sun. I have a window box on the house with artificial geraniums (designed for outdoor use) and the leaves turned faded purple in about a month. Autumn and holiday decorations hold up well...just struggling with floral ideas that will not fade! I would love to grow chives in the boxes but not sure they will even make it.