Today's vehicles are normally equipped with more than one brake warning light on the instrument panel. Regardless of what warning light is lit, it is an indication of warning to the driver. You need to understand what would cause the different lights to illuminate in order to take care of the problem. Keep in mind, a vehicle may have one, two, or all of these lights.
The red warning light indicates there is a problem in the regular brake system, such as low brake fluid levels or that the parking brake is on. A low fluid light may be present in addition to the red brake warning light. Whenever the fluid is low you should suspect a leak or very worn brake pads.
The yellow or amber brake warning light is tied into the antilock brake system. This light turns on for two reasons: the antilock brake system (ABS) is performing a self-test or there is a fault in the ABS.
A blue warning light lets the driver know the wheels are slipping because of poor road conditions.