there are usually different ways of writing these lists, for example when creating websites. the most common way uses hexadecimal code, in which the numbers ranging from 0 to 255 can be represented using 2 digits. this only needs six hexadecimal digits (which may be the numbers 0-9 or the letters a-f) to represent rgb colors. when using hexadecimal code, these digits are preceded with a '#' character. see the examples section below.