Ate has been a favorite brake fluid manufacturer for those of us that are higher performance car floggers, or at least think we are. It has a nice high (dry) boiling point 536 F and wet at 392 F. It also, for the last 15 years, came in two colors, blue and yellow.
Why? Well for those fanatical track day types who bled their brakes between every event it was critical to be certain that you had flushed out all the “old” fluid. Swapping between the two colors would give you a strong visual clue that you had done so. If you had been running the yellow and were bleeding the brakes you would know that it was complete when the blue stuff showed up at the bleeder. If you had used the blue stuff you switched to the yellow and could tell you had completed the job when yellow fluid had displaced the blue.
A great, high performance brake fluid and all was right with the world until someone in DOT woke up and viewed the brake fluids.
While it will be perfectly legal to be sold in every other country in its blue form, in the US it is now illegal. Technically it has been for 15 years.
The Federal Motor Vehicle Safety Standard requires that all brake fluid sold in the US be either clear or amber in color. Apparently this is so that if fluid is leaking it can be quickly attributed to the source. All ATF (automatic transmission fluid) must be red in color in the hopes that if the system is leaking the red fluid will still be recognizable and attributed to the proper source of the leakage.
I suppose there also might be a concern that someone might mistake blue brake fluid for blue windshield washer fluid or visa versa.
Thankfully Ate (Alfred Teves Engineering, a division of Continental tires) yellow will still be available with all the high performance properties we’ve come to know and love.