How are 4 and 5 digit hex color codes represented? [closed]

Question

When I use #FF22 or #FF444, what rules turn it into a color? I know that hex codes should be 6 digits, or 3, but this works in chrome.

Answer 1

There is no 4 digit hex color. 3 digit hex color is converted into 6 digit hex color by copying each character next to each to other. For example, #f0f is expanded to #ff00ff.