Convert 3 digits color to 6 digits color

JavaScript version
const toFullHexColor = (color) =>
`#${(color.startsWith('#') ? color.slice(1) : color)
.split('')
.map((c) => `${c}${c}`)
.join('')}`;
TypeScript version
const toFullHexColor = (color: string): string =>
`#${(color.startsWith('#') ? color.slice(1) : color)
.split('')
.map((c) => `${c}${c}`)
.join('')}`;
Examples
toFullHexColor('123'); // '#112233'
toFullHexColor('#123'); // '#112233'
toFullHexColor('#abc'); // '#aabbcc'