A very fast color rough-out, all on one layer just to quickly start working toward what I see in my head:
I just wanted to have a loose place to start from, playing with a little bit of color. I really feel like I have to compress my process and run as fast as I can with it, so I'm not doing a grayscale value pass or tightening up any details on the sketch. I'm just going to try to trust myself to find that image that I see in my head with the paint, and hope it doesn't come back to bite me, heh.
Below, the same image without the pencil sketch:
So now on to the first real passes at the main components. I'm going to start with the main subject and hopefully center of attention, our hero Mr. Crabthwaite...
...and his Tortoise machine.
I'm seeing the Tortoise as having copper exterior plating on the shell, at least the top half and the head, with the darkish blue-grays and blacks of cast iron and steel for the frame, load-bearing legs and other structural details. It's going to be a fairly rough finish compared to the Hare, which will have a lot of shiny metal cladding and some painted colors on it. Our Mr. Crabthwaite built it in his backyard out of whatever he could get his hands on, with a shoe-string budget, where the Commodore had his own personal fortune and backing from other wealthy investors.