Converts a literal color string (i.e. white) to a color rgb.  Also accepts
    hex strings or single characters from the following list.

        b: blue
        g: green
        r: red
        c: cyan
        m: magenta
        y: yellow
        k: black
        w: white

def string_to_rgb(string):
    """
    Converts a literal color string (i.e. white) to a color rgb.  Also accepts
    hex strings or single characters from the following list.

        b: blue
        g: green
        r: red
        c: cyan
        m: magenta
        y: yellow
        k: black
        w: white

    """

    # if a single character
    if len(string) == 1:

        # Convert from single character to full hex
        if string.lower() not in color_char_to_word:
            raise ValueError('Single character string must be one of the following:'
                             '\n%s' % str(color_char_to_word.keys()))

        colorhex = hexcolors[color_char_to_word[string.lower()]]

    # if a color name
    elif string.lower() in hexcolors:
        colorhex = hexcolors[string.lower()]

    # try to convert to hex
    else:
        try:
            return hex_to_rgb(string)
        except:
            raise ValueError('Invalid color string or hex string.')

    return hex_to_rgb(colorhex)