Architects, Designers and the like often fall into the trap of specifying the individual tactile dots. These individual tactile dots are called discrete tactiles. Discrete tactiles are required by AS1428.4.1 – 2009 to have a minimum allowable luminance contrast ratio of 45%.
This usually catches people out as most people know about the 30% contrast ratio but haven’t come across the 45% or the 60% (composite discrete tactiles) requirements.
For example, see pictures below of where these discrete tactiles do not have sufficient contrast ratios.