code: private static Colour  parseColourKeyword(String nameLowerCase) throws SVGParseException
     {
        Integer  col = ColourKeywords.get(nameLowerCase);
        if (col == null) {
           throw new SVGParseException("Invalid colour keyword: "+nameLowerCase);
        }
        return new Colour(col);
     }
docs: Parse a colour component value (0..255 or 0%-100%)