Converts a color from "color", (255, 255, 255) or "#ffffff" into a color tk 
    should understand.

def convert_color(color):
    """
    Converts a color from "color", (255, 255, 255) or "#ffffff" into a color tk 
    should understand.
    """
    if color is not None:

        # is the color a string
        if isinstance(color, str):
            # strip the color of white space
            color = color.strip()

            # if it starts with a # check it is a valid color
            if color[0] == "#":

                # check its format
                if len(color) != 7:
                    raise ValueError("{} is not a valid # color, it must be in the format #ffffff.".format(color))
                else:
                    # split the color into its hex values
                    hex_colors = (color[1:3], color[3:5], color[5:7])

                    # check hex values are between 00 and ff
                    for hex_color in hex_colors:
                        try:
                            int_color = int(hex_color, 16)
                        except:
                            raise ValueError("{} is not a valid value, it must be hex 00 - ff".format(hex_color))

                        if not (0 <= int_color <= 255):
                            raise ValueError("{} is not a valid color value, it must be 00 - ff".format(hex_color))

        # if the color is not a string, try and convert it
        else:
            # get the number of colors and check it is iterable
            try:
                no_of_colors = len(color)
            except:
                raise ValueError("A color must be a list or tuple of 3 values (red, green, blue)")

            if no_of_colors != 3:
                raise ValueError("A color must contain 3 values (red, green, blue)")

            # check the color values are between 0 and 255
            for c in color:
                if not (0 <= c <= 255):
                    raise ValueError("{} is not a valid color value, it must be 0 - 255")

            # convert to #ffffff format
            color = "#{:02x}{:02x}{:02x}".format(color[0], color[1], color[2])

    return color