Here are the possible solutions for body art colloquially and this puzzle's theme clue
Answer
Clue
Relevancy
ink
Clue
Body art, colloquially, and this puzzle's theme
Definition
a coloured liquid used in writing
lllllllllllllllllllll
Clue
Much of the Smurfs' theme song, and this puzzle's theme
standbyme
Clue
1986 movie based on the Stephen King novella "The Body" ... and this puzzle's theme
tat
Clue
Body art, briefly ... and, initially, a hint to this puzzle's four longest answers
wordladder
Clue
Puzzle invented by Lewis Carroll (and a hint to this puzzle's theme)
info
Clue
Theme word inside this puzzle's theme words
Definition
(short for) information
rawhide
Clue
Classic TV theme song covered by this puzzle's theme duo
Definition
to beat with a type of whip
four
Clue
Number of times this puzzle's theme word appears diagonally in the grid (to complete the puzzle, shade those words plus the Down answers that begin where they meet)