This function returns the amount of blue used to make the given colour, with the value being between 0 and 255, where 0 is no blue and 255 is all blue. The following image illustrates this:
|col||The colour to check|
b_comp = colour_get_blue(c_teal);
The above code will get the blue component of the colour constant "c_teal" and store the value in the variable "b_comp".