There is a color that is denoted by 0x000000 , and there is # 000000 .

How is the difference between them correctly called?

Here is the first option, if I’m not mistaken 16-riche format ..

Answer 1, Authority 100%

In no way, these are simply different characters for the designation of the same sixteenth digit format of the number. Unlike you, the interpreter you just need to know what kind of number system you use there and to distinguish somehow bases, different characters are affixed. In this case, both symbols mean the same 0x {hex} = # {hex} = hex.

As a rule, it is simply said about the “form” form form.

Answer 2, Authority 50%

and second too)) hex if otherwise