Red Gold is 5.5% copper and 94.5% Gold
Pink Gold is 6% silver, 19% copper, 10% palladium, 5% nickel and 60% pure gold
Just to be clear on the matter. There can be slight changes in these formulations, but these %'s represent the bulk of the Red vs. Pink Gold alloys used in watch making. I have had several conversations on and off line lately where many collectors and even some retailers were not aware of the difference in the two alloys. I am more of a White Gold fan myself (10% copper, 10% palladium, 5% nickel and 75% pure gold) but that is just personal taste.
Maybe one of the Hour Lounges has a good comparison photograph and then we can really put the issue to bed.
This information is also published off line in the V&C desk top calendar.
Best to you all,