its so easy part only you have to do is just study which digit every colour represent to.
since resistor is a very small device it is not practical to type its resistance value ,tolerance etc on it.so colour code is a method to express such info, in an easy way
the following colour codes are commonly used
to study the colours in order just by heart a sentence
BB ROY of Great Britan had a Very Good Wife
(capital letters resemble order of colours)