def formatCodes(codestr):
    """Color by PEM type."""
    if 'ACC' in codestr:
        return 'k.'
    elif 'MIC' in codestr:
        return 'b.'
    elif 'SEIS' in codestr:
        return 'r.'
    elif 'MAG' in codestr:
        return 'y.'
    elif 'RADIO' in codestr:
        return 'g.'
    elif 'V' in codestr:     # Voltmeters
        return 'c.'
    else:                    # Empty set
        return 'k*'