How to convert 3-digit HTML hex colors to 6-digit flex hex colors

Question

I want to convert a three-digit hex color which is coming from HTML CSS to a six-digit hex color for Flex. Can anyone give me code to convert 3-digit hex colors to their 6-d

Answer 1

Double every digit: for example #A21 is equal to #AA2211.

However this question is a duplicate of: convert to 3-digit hex color code