### RGB to hexadecimal

Convert given RGB parameters to hexadecimal string using bitwise left-shift operator (`<<`) and `toString(16)`, then `padStart(6,'0')` to get a 6-digit hexadecimal value.

```js
const rgbToHex = (r, g, b) => ((r << 16) + (g << 8) + b).toString(16).padStart(6, '0');
// rgbToHex(255, 165, 1) -> 'ffa501'
```