I may be able to clear this up a little.
Just like a traffic signal, yellow means caution and red means stop.
Some of the dash lights are yellow for caution and some are red for "this is an emergency, take care of me NOW".
The check engine light (as well as some others) is yellow.
The dash brake warning light (as well as some others) is red.
With that said, there are some older cars (before smog laws dictated a "malfunction indicator light) that had a light that combined engine coolant overheating with low oil pressure. These were also labeled "check engine" lights, and the "check engine" light on these cars are red.
Sometimes explanations about the lights and their colors gets mixed up or lost in the translation.
