def _return_default_colors_rgb(**kwargs):
    """Replace color in kwargs with pyfar default color if possible."""

    # pyfar default colors
    colors = {'p': '#5F4690',  # purple
              'b': '#1471B9',  # blue
              't': '#4EBEBE',  # turqois
              'g': '#078554',  # green
              'l': '#72AF47',  # light green
              'y': '#ECAD20',  # yellow
              'o': '#E07D26',  # orange
              'r': '#D83C27'}  # red

    if 'c' in kwargs and isinstance(kwargs['c'], str):
        kwargs['c'] = colors[kwargs['c']] \
            if kwargs['c'] in colors else kwargs['c']
    if 'color' in kwargs and isinstance(kwargs['color'], str):
        kwargs['color'] = colors[kwargs['color']] \
            if kwargs['color'] in colors else kwargs['color']

    return kwargs