I also struggled with paint color when building the trainroom. I did want a blue, but what shade. You get mindboggled looking at the color swatches, and wow.....they usually come out looking a lot different once applied to a large wall area. My room is about 16'x22', and I have 8 double tube recessed flourescent lights, as well as another 8 track lights on dimmers, which work well for more of a "softer" look.
I purchased my paint from a store chain we have called, oddly enough "Canadian Tire", similar to a "Lowes" or "Home Depot", minus the lumber part. Anyway it was their store brand paint called "Roccoco Blue", which I don't know if it is a standard color available from other brand name paints or not.
I'm very happy the way it turned out. Ended up a nice "Mid" tone blue, which to me seems to closely resemble a "sky" color. I hope to someday find someone with artistic skills a lot better than mine, and have distant hills and clouds painted directly on the walls. Nothing with a lot of detail, just something to add a little depth.
Here's a couple of pics showing the early construction, and later with the layout, still far from completed.
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