Introduction to Colouring

Today's Puzzle:

An opportunity to spend your afternoon colouring a lovely Sudoku puzzle. Whom can resist?

Link to Play Along:

Introduction to Colouring by Silverscree https://tinyurl.com/SudokuSleuthColouringIntro

Rules:

Normal 6×6 sudoku rules apply; place the digits 1 to 6 exactly once each in every row, column, and box.

Anti-king: cells that are diagonally adjacent may not share a digit.

Palindromes: the grey lines form palindromes; they read the same set digits either way you read them.

Little killer: the digits along the indicated diagonals sum to the given total. Digits may repeat if allowed by other rules.