In Arduno it works fine (as there are #defines in the Binary.h file which define all of the 8bit binary numbers). However in C, binary literals are not part of the specification so the strictest of compilers just spit them out.
With GCC, there is built in support for binary literals, so you can use things like 0b or 0B to denote a binary number. It is beyond me why the people at Arduino decided to define there own binary numbers rather than use the GCC ones.