Post History

Expand a greyscale/colour hex code

Consider a type of hexadecimal colour code that supports shorthand for both greyscale and colour:
- A 6 digit code is interpreted as 2 digits for red, followed by 2 for green, then 2 for blue.
- A 2 digit code is greyscale. The 2 digits are repeated for each of red, green, and blue.
- A 3 digit code is shorthand for a 6 digit code with repeated digits for red, green, and blue.
- A 1 digit code is shorthand for a 2 digit greyscale code with the same 1 digit repeated.

## Input
- A colour code in the format "#" followed by 1, 2, 3, or 6 hexadecimal digits.
- You may take input as either a string or any ordered sequence data type.

## Output
- A colour code in the format "#" followed by 6 hexadecimal digits.
- The output after the "#" depends on the number of hexadecimal digits in the input as follows:
  - Input with 1 digit: output the 1 digit 6 times.
  - Input with 2 digits: output the 2 digit string 3 times.
  - Input with 3 digits: output each digit twice (rather than the 3 digit string twice).
  - Input with 6 digits: output the same 6 digits.
- You may output as either a string or any ordered sequence data type.

## Test cases
Test cases are in the format `Input : Output`.

```text
#0 : #000000
#2E : #2E2E2E
#ACF : #AACCFF
#012345 : #012345
```

## Scoring
This is a [code golf challenge]. Your score is the number of bytes in your code.

> Explanations are optional, but I'm more likely to upvote answers that have one.


[code golf challenge]: https://codegolf.codidact.com/categories/49/tags/4274 "The code-golf tag"