def to_ansi
      return to_depth(8).to_ansi if depth != 8
      a = ANSI_COLORS.map{|c| self.class.const_get(c.to_s.upcase) }
      a.map!{ |c| self.euclidian(c) }
      ANSI_COLORS[a.index(a.min)]
    end
def to_ansi
      return to_depth(8).to_ansi if depth != 8
      a = ANSI_COLORS.map{|c| self.class.const_get(c.to_s.upcase) }
      a.map!{ |c| self.euclidian(c) }
      ANSI_COLORS[a.index(a.min)]
    end
convert to ANSI color name