Title: Colors Have Been Twinned

Rating: 4/5

The official rules:
 The digits 1 through 9 appear in each row and each column exactly once.
 Digits in each shaded region must add to the indicated sum.
 Squares with multiple colors contain a number that’s used in the sum for adjacent regions of each of those colors.
 Remember: numbers can repeat within a shaded region if that doesn't violate the first rule.