Red ones work for any security controlled aerodrome, others are just for the place of issue I believe (?)
Not exactly. A red ASIC is required for unescorted access within a Security Restricted Area (SRA). A grey ASIC is for other airside areas. Most ASICs though are produced as red except for some f the smaller regional airport specific ones and staff at larger airports who have no need to be on aprons such as those who work in cafes and airline lounges.
The black text on the red background was always a pain but the example in the regs was displayed that way. Many issuing bodies from the outset though produced cards with white font. In the next round of regulation changes, white will be specified for all ASICs (except white ASICS 😀
