It's new Cat yellow that I was mixing with orange. The old Cat yellow is a beautiful colour though, much nicer than the Federal yellow Case used to use. Keep in mind that Cat paint will start to fade in the 3rd year and just keep getting paler and lighter, unless inside.
Never tried to mix up the power tan colour. Brown might be the additive colour.
Mixing colours does not really follow any logical path and it's tough to find anyone who knows what colour to add. My son finally found the info on the internet somewhere.
The brown that Case uses on their cabs can be mixed by adding red to any dark brown colour. We mixed a large batch of it, using recycled brown paint, of different shades, and lots of fire engine red. Used a piece of cardboard and just kept dobbing a sample on it until it matched that expensive Case paint. Phil
