To Generate random color just click on "RGB to HEX Color"
It takes input in the form of values for Red, Green and Blue ranging from 0 to 255 and then converts those values to a hexadecimal string that can be used to specify color in html/css code. Photo editing software usually represents color in RGB and therefore if you would like to use the colors you use in your photo editing software as the background of your html element then you will have to get the hexadecimal representation of the RGB values. This tool allows you to get those values.
Perhaps you have seen a hex code on a web page and would like to use that color in your photo editing software. In that case you will need the RGB values if your photo editing software does not support hex values.