I think I solved the mystery.
Both
Red and Pink are the same (or similar enough to produce comparable performance).
I just changed the coolant on my 2004 Lexus LS430. The coolant was
red (Lexus dealer last changed it when replacing the water pump and timing belt at the 100k service).
Red coolant on a 2004 model is expected, since Toyota didn't start using pink coolant until 2005.
BUT, the maintenance schedule (which is also what the dealer followed) on the 2004 says to change coolant after
100,000 miles / 10 years, and 60k / 5 years thereafter! This is the same schedule they are recommending for the 2005 model that uses the pink stuff!
In addition, the 2004 manual says to use Super Long Life coolant, but every maintenance schedule for model year 2004 lists the red coolant, which is also what the Lexus dealer is using for that model year.
At this point, Lexus would have surely caught their mistake and update their dealers to follow a different maintenance schedule appropriate for the red coolant, but they haven't.
Here is what I think happened:
Toyota has continuously improved their red coolant, but hasn't changed their maintenance recommendations. In 2005, they were confident that their red stuff has evolved enough to switch from 30k miles / 2 years to 100k miles / 10 years for new cars, and 60k / 5 years thereafter. That's a big jump. So they gave it a different color, released it as pre-mix (which ensures that the correct ratio and water type is used which does affect its life), and named it Super Long Life.
Similarly, on paper Honda's coolant hasn't changed since 1990 when they started using the blue premix on every Honda. Just like Toyota, they must have gradually improved it overtime, because I doubt that Honda had coolant in 1990 that is now advertised to last 10 years in new cars, whereas Toyota supposedly only figured out that formula in 2005.
Why are the ingredients on the bottle different?
They don't have to put all the ingredients on the bottle. For example, Peek Long Life Coolant doesn't list 2-EHA as an ingredient on the bottle, but it is on the MSDS.
Similarly, even if ingredients are listed on the bottle, that doesn't mean they are also on the MSDS. This is the case for both Red (
http://www.worldpac.com/tagged/SDS_00272-1LLAC_Toyota_Genuine_Coolant.pdf) and Pink (
http://www.worldpac.com/tagged/Toyota_super_long_life_coolant.pdf) coolant, which show ingredients on their bottles that are not listed on the MSDS.
Essentially, manufactures can pick and choose what they are listing as ingredients on the bottle, and can also decide what to list on the MSDS as long as the amounts are small enough to not be hazardous (which is true for inhibitors). This means that what is listed as an ingredient on the red bottle can still be in the pink bottle (and vice versa).
Either way, the red coolant lasted for 100k miles without damaging the water pump or radiator, which would be a long stretch considering that the red stuff supposedly only lasts for 30k / 2 years. When I drained the red stuff 6 years later, it again looked like new.