Originally Posted By: dailydriver
^^^No, it was the color ONLY, since all of the other racing DOT 4/4+ companies are allowed to use "DOT 4" on their labels/copy,
-snip-
Apparently, they were afraid that the color would confuse consumers, and techs into pouring the wrong fluid into the right component.
Or at least that was the excuse/rationale they gave for the ban.
The law about brake fluid, FMVSS 116, has been around since 1972, so it predates Super Blue by a wide margin. It's also the only automotive fluid directly regulated by the government/DOT.
non-silicone DOT 3/4/5.1 clear or amber
silicone DOT 5 purple (defined as at least 70% silicone)
mineral oil (LHM, CHF, etc) green
Mixing DOT 5 silicone with regular 3/4/5.1 WILL cause damage! The whole solution will turn to a thick goo. And mineral oil can't be mixed with brake fluid, either.
The clear/amber color gets black as the fluid absorbs moisture.
The standard also specifies viscosity limits, and compatibility with materials commonly used in brake systems.
The fluids don't have to be miscible with *each other*, they just have to compatible with the seals and components in the system.
The racing fluids you mention all meet the standard on paper and comply with FMVSS 116 as written. Although the SRF seems to react with magnesium, making it inappropriate for Z06's. They should recall SRF!
Super Blue said DOT 4 on the can even though it didn't comply with FMVSS 116. They're also NOT allowed to say "meets DOT 4 except the color" or "complies with FMVSS116 except the color requirement". However they could say "meets SAE J1703/J1704 except the color" because the SAE is a private organization and not the government.
I do wish they'd ban BLACK brake fluid though!