This is a Sublime Text 3 syntax definition for the SREC file format. It's designed to help with inspecting your hex files by setting a different color for a record's length, address, type, data and checksum allowing to more easily distinguish them.
The scopes have been somewhat hackisly chosen to be consistent with the SREC_HEX template on Wikipedia when using Sublime Text's default Monokai color scheme. They have no other meaning in any way.
Original idea from @seppestas work on Intel HEX.