A Quick Question

[rickb773]

Now that I am the proud owner of a set of 12 Doc O’Brien’s weathering powders (most of which look the same to my red/green color blind eyes), I have to ask: is there a chart of how to weather cars for a partially color blind neophyte (such use color X around the hatches of a covered hopper in cement service)?

(I can dream can’t I?  )

[Cajonpassfan]

Oh Rick, that's a tough one. But cement hoppers should be relatively easy (no green or red there )
Here's a shot of ATSF cement hoppers at Summit, Cal. It's "cement" over mineral red; any light whitish gray color should do for the streaks...
Have fun 
Otto K.

[DeltaBravo]

Go easy on the black and the rust, a little goes a long way. Practice on a couple of your old stock or go to a train show and buy some old broken cars.

[Rich_S]

Rick, I read an article about Rod Stewart, he's color blind and a model railroader. He has a small group of people that helps him on his layout. I guess one weekend he decided to do some scenery work when none of them were around. The next time they stopped over, he asked everyone how the new scenery looked and their answer was, why is everything so red?

Cement is a light gray to white in color. I don't own any Doc O'Brien's weathering powders, but it looks like they list highlight white and some type of gray. You would want to use a combination of the white and gray to simulate where the cement powder spilled onto the car.  The rusty red looks like it would be for fresh rust and the rusty brown looks like it would be used for older rust. I would say, use light coats then run the car past your operating crew for their opinion. Also as Otto suggests, always weather your models using a photo of the prototype, the prototype photo will take a lot of the guesswork out of weathering. Good luck in your efforts and please show us your accomplishments.