Subject #6 Sign Blockdata Command

/blockdata ~ ~-1 ~ {Text1:"[\"\",{\"text\":\"Test Subject\",\"color\":\"dark_gray\",\"bold\":true}]",Text2:"[\"\",{\"text\":\"#6\",\"color\":\"black\",\"underlined\":true}]",Text3:"[\"\",{\"text\":\"Power:\",\"color\":\"light_purple\",\"bold\":true}]",Text4:"[\"\",{\"text\":\"Corrosive\",\"color\":\"green\"}]"}