How to know the Color Code of any Random Color (In HTML)?

Question

I have played alot of SoloLearn Games on HTML but there is a particular type of question in which I mostly select a wrong answer & that type of Question is : What is the Color Code of *xyz* Color. How can I get correct answer of such questions?

Answer 1

hexadecimal is
#rrggbb, with r being red, g green and b blue.

0 means nothing of that color and F is the most

so:
#FF0000 = red
#00FF00 = green
#0000FF = blue

rgb is
rgb(r, g, b), with r being red, g green and b blue

0 means nothing of that color and 255 thr most

so:
rgb(255, 0, 0) = red
rgb(0, 255, 0) = green
rgb(0, 0, 255) = blue

Answer 2

RBG is divided by hex number
that is 16