http://www.rfc-editor.org/rfc/rfc7308.txt
RFC 7308: Extended Administrative Groups in MPLS Traffic Engineering (MPLS-TE), E. Osborne2014-07-01T23:00:00-00:00This document adds a sub-TLV to the IGP TE extensions, "Extended Administrative Group". This sub-TLV provides for additional administrative groups (link colors) beyond the current limit of 32.