While it seems like I have been spending a lot of time on this diorama in the past week, the actual results seem somewhat sparse! Isn't that the way with this hobby!
Well, I got the airbrush out to give some color to stone walls for the bottom level of the diorama. I have a base layer of flat black paint (above), and painted on some Tamiya Medium Grey (below) at a sharp angle to preserve as much 'black' in the shadow areas as possible.
While the airbrush was out, I also gave the track a shot of Tamiya Red-Brown for rusty rail look. This is the same color I used on my layout and I think it looks really good. Side note that after just using the grey, and then switching to the red brown, the air brush then started to get all problematic on me. It seems with Air Brushes that you spend as much - or even more? - time cleaning them than you actually use them for painting!
Wallah! Now with a bit more concrete color, the bottom level starts to take on a bit more shape...but I'm not done yet!
Using my homemade decal sheets, I applied some graffiti to the stone work, tunnel portal, etc...
That graffiti should give me just enough of a gritty, urban environment that I want with this diorama!
I'm not sure when to do the track work or ballast...I still have to work out the middle and top layers, so I am thinking of getting all of the mechanical aspects out of the way before I go too crazy with track and ballast and that sort of thing. Hopefully I will have more progress to share shortly!