Add color command

lib/uplot/plot.rb

@@ -123,6 +123,18 @@ module Uplot
       UnicodePlot.boxplot(headers, series, **params.to_hc)
     end
 
+    def colors
+        UnicodePlot::StyledPrinter::TEXT_COLORS.each do |k,v|
+          print v
+          print k
+          print "\t"
+          print "  ●"
+          print "\033[0m"
+          print "\t"
+        end
+        puts
+    end
+
     def check_series_size(data, fmt)
       series = data.series
       if series.size == 1