That things in good hands
Edit: I need to read closer, I thought you were doing a commission, I didn't realize this was one of YOUR casts! Is this of the "Yet Another" scratch build?
After a few passes of Krylon primer and wet sanding, I airbrushed the dark gray layer over the entire helmet. For the dark gray I used Tamiya XF-24 dark gray with a few drops of XF-2 white, about 20:1. It's all pretty subjective. This happened to look good to me.
White graphite transfer paper to get the gray sections. I left some gray areas to fill around later with the topical silver and light gray.
Finally I apply masking fluid and airbrush Testors Model Master Concrete Flat.
Here is me giving RLM73 a try. It's the Testors Model Master iteration of the color, it looks pretty legit to me. So much grittier than the bright-blue green color I'm used to. Kinda badass.
I feel you brother. When I get home from work and look at whatever project I have going I am also intimidated. I find it helps to focus only on the step I'm doing at the moment. I tend to get bogged down trying to process everything that needs to be done at once.
Progress...I used Model Masters Panzer Olive Grun and Tamiya Flat white with a ratio of about 4:3 to give me a minty fresh dome and cheeks. The POG has a nice mix of blue and green, but straight from the bottle was too dark for the look I'm going for with this bucket. I'm thinking a 2:1 mix would probably have worked just as well.
Maroon layer consists of Model Master Caboose Red with a few drops of MM Dark Blue. I really don't make a big fuss over this...it's basically some type of red with a little of a deepish blue.