The first 2 color codes gives the integer value of the resistance example:- if 1st color is red then the first value of resistance is 2
And if 2nd one is orange then the second integer value is 3
The third color is used in power of 10
Like if the 3rd color is blue then it goes as 10 to the power 6. And last color shows tolerance as +- % if silver is there then 5%
So the code becomes 23 x 10_6 +- 5%