syn match snipComment '^#.*'
syn match placeHolder '\${\d\(:.\{-}\)\=}' contains=snipCommand
syn match tabStop '\$\d'
syn match snipCommand '`.\{-}`'
syn match snippet '^snippet.*' transparent contains=multiSnipText,snipKeyword
syn match multiSnipText '\w\+ \zs.*' contained
syn match snipKeyword '^snippet'me=s+8 contained

hi link snipComment   Comment
hi link multiSnipText String
hi link snipKeyword   Keyword
hi link snipComment   Comment
hi link placeHolder   Special
hi link tabStop       Special
hi link snipCommand   String