Exercise Points$]$: Webcolors can be expressed with six base$-16($hexadecimal$)$ digits $($two each for the red, green and blue components, in that order$)$ prefixed with #$.$ The hexadecimal format uses sixteen distinct symbols, most often the symbols $0-9$ to represent values $0$ to $9,$ and A$-$F $($or alternatively a$-$f$)$ to represent values from ten to fifteen.

a$)$ How many separate shades are there in each channel of an RGB triplet and in total?

b$)$ How are black and white written in this format?

c$)$ Convert the hexadecimal colour #$00$b$0$ff into an RGB triplet.

d$)$ CMYK colours encode four channels $($cyan$,$ magenta, yellow and black$),$ taking values between $0-100($inclusive$).$ Are there more possible colours in the CMYK scheme than hexadecimal?