I can get Graphite Brown Metallic mixed at the paint supply store I use here but they have no samples of it and can't seem to access it on their monitor. Also, I have not been able to find anyone here who has posted an image of it, so I'm not certain what it will look like. Does anyone have a good image of it...something they've shot or the interior of their truck? I'm in the process of repainting the truck, and I've settled on a Chevy color named Bright Red (PPG 3794) which is close to the 1952 Swift Red but a darker red by a shade or two. If you're curious, Swift is to the left and Bright Red is to the right:
https://beta.photobucket.com/u/JonGoodman/p/ad7295b9-d96a-4117-87f2-8da8a0000189Popular Corvette and Blazer color in the early to mid 90s.
If you have an example of the Graphite Brown Metallic, please let me know.