In the UK they are different colours and patterns so blind and partially sighted folks can tell what they're near. They're red near pedestrian controlled light

In the UK they are different colours and patterns so blind and partially sighted folks can tell what they're near. They're red near pedestrian controlled lights and yellow near uncontrolled lights or crossings with no lights. There's different patterns of the raised dots/lines for some uses - like steps or platform edges. None of this had I noticed until someone pointed out there was a method at work. :)