How to get hexadecimal colour value from Python API?

[Bao Niu <niubao56 gmail com>]

Now if I want to extract colour value for an object from Python API, there is only one form, namely decimal RBG value, and even worse, they are three separate attributes (value.red, value.blue, value.green), is there a way to extract a single hexadecimal colour value? Or at least extract a grouped RBG value from one call instead of three different calls? Thanks.