Andy, my apologies for not being a bit more specific. I've got a load of HO scale street lamps which are white LEDs which will be used to light the bridges and possibly the yard. The blue LED reel is to light the whole layout, and will be stuck on the underside of the APA box lid, which will be placed over the layout to create a "shadow box" as it were. Lighting a layout with blue LEDs does give an excellent "moonlight" type effect, as demonstrated in here: https://model-railroad-hobbyist.com/node/32405 I already have a reel of white LEDs which might end up going alongside the blue ones for if I want to do a "day/night" cycle. We'll see how things go.