For example:

int red= 0xFF，green=0x80，blue = 0xaa

0xFF, 0x80 and 0xaa are hexadecimal integers.

% x- is the format definition in the output/input statement.

For example:

int y；

scanf("%x "，& ampy)； //Enter an integer in the form of 16.

printf("%x %d "，y，y)； //% x- output y in the form of 16, %d-output y in the form of 10.

If you type 0x 123 or 123, it means 16.

Output: 123 29 1