Hi Statlist,

I would like to plot a density so that it displays a grayscale going from white on the extreme left part to black in the extreme right part.
My code is as follows:

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input float(log_lag_tot_sales log_lead_tot_sales log_lagged2_tot_sales log_lead2_tot_sales)
         .          .         .          .
         .   11.57562         .  11.556605
   10.6708  11.556605         .   6.168915
  11.57562   6.168915   10.6708  1.6467954
 11.556605  1.6467954  11.57562          .
  6.168915          . 11.556605          .
         .   10.74079         .          .
  14.58203          .         .          .
         .          .         .          .
         .  11.118983         .  11.331554
 10.865294  11.331554         .  11.343142
 11.118983  11.343142 10.865294  11.336972
 11.331554  11.336972 11.118983   11.55704
 11.343142   11.55704 11.331554  11.473188
 11.336972  11.473188 11.343142   11.52564
  11.55704   11.52564 11.336972  11.655797
 11.473188  11.655797  11.55704   11.63217
  11.52564   11.63217 11.473188  11.290495
 11.655797  11.290495  11.52564  10.561643
  11.63217  10.561643 11.655797          .
 11.290495          .  11.63217          .
         .    3.34627         .  2.9033904
 3.5634015  2.9033904         .   2.662851
   3.34627   2.662851 3.5634015          .
 2.9033904          .   3.34627          .
         .          .         .          .
         .   6.938858         .          .
   12.3347          .         .          .
         .  14.290753         .  14.203842
 14.289332  14.203842         .  14.459516
 14.290753  14.459516 14.289332   14.51494
 14.203842   14.51494 14.290753  14.752728
 14.459516  14.752728 14.203842  14.711233
  14.51494  14.711233 14.459516  14.565996
 14.752728  14.565996  14.51494   12.56849
 14.711233   12.56849 14.752728  .57972085
 14.565996  .57972085 14.711233  11.687688
  12.56849  11.687688 14.565996  11.903893
 .57972085  11.903893  12.56849          .
 11.687688          . .57972085          .
         .  10.056931         .   9.288839
 10.000427   9.288839         .   8.336972
 10.056931   8.336972 10.000427   8.602725
  9.288839   8.602725 10.056931   9.005105
  8.336972   9.005105  9.288839   8.550479
  8.602725   8.550479  8.336972   8.761358
  9.005105   8.761358  8.602725   8.991681
  8.550479   8.991681  9.005105   9.026819
  8.761358   9.026819  8.550479   8.825924
  8.991681   8.825924  8.761358   8.781609
  9.026819   8.781609  8.991681          .
  8.825924          .  9.026819          .
         .          .         .          .
         .   8.611331         .  9.3185625
  7.614491  9.3185625         .   9.180587
  8.611331   9.180587  7.614491   9.650503
 9.3185625   9.650503  8.611331   9.102926
  9.180587   9.102926 9.3185625   9.308524
  9.650503   9.308524  9.180587   9.465543
  9.102926   9.465543  9.650503          .
  9.308524          .  9.102926          .
         .   5.454896         .   5.640154
  7.190414   5.640154         .          .
  5.454896          .  7.190414          .
         .   .6292556         .  1.1384683
 1.6762704  1.1384683         . -.26826787
  .6292556 -.26826787 1.6762704   .7881434
 1.1384683   .7881434  .6292556          .
-.26826787          . 1.1384683   6.743719
         .   5.427053  .7881434   4.817077
  6.743719   4.817077         .   4.873231
  5.427053   4.873231  6.743719          .
  4.817077          .  5.427053          .
         .   5.668871         .   5.276427
  5.821651   5.276427         .   .3716027
  5.668871   .3716027  5.821651          .
  5.276427          .  5.668871          .
         .  10.069922         .   10.24204
 10.129775   10.24204         .   9.494603
 10.069922   9.494603 10.129775   8.728362
  10.24204   8.728362 10.069922   8.757013
  9.494603   8.757013  10.24204   8.681924
  8.728362   8.681924  9.494603   8.750833
  8.757013   8.750833  8.728362   8.979093
  8.681924   8.979093  8.757013  8.8749075
  8.750833  8.8749075  8.681924   8.915873
  8.979093   8.915873  8.750833   8.884404
 8.8749075   8.884404  8.979093          .
  8.915873          . 8.8749075          .
         .   10.20618         .   5.027871
  10.34363   5.027871         .   2.919647
  10.20618   2.919647  10.34363          .
  5.027871          .  10.20618          .
         .   5.309826         .   2.843353
  5.749509   2.843353         .          .
  5.309826          .  5.749509          .
         .   12.95111         .  13.288822
 12.489015  13.288822         .   13.39754
  12.95111   13.39754 12.489015   13.32778
 13.288822   13.32778  12.95111  13.493407
end
Code:
twoway (kdensity log_lag_tot_sales if recalled_class_two ==1, lcolor(red) lpattern(solid)) (kdensity log_sales if recalled_class_two ==1,lcolor(blue) lwidth(medthin) lpattern(dash)) (kdensity log_lagged2_tot_sales if recalled_class_two ==1, lcolor(green) lwidth(medium) lpattern(longdash_shortdash)), title(Sales (logarithmic scale):) subtitle(density one and two years before the recall)  ytitle(Density) xtitle(Logarithm of total sales) legend(order(1 "sales one year before recall" 2 "growth sales current year" 3 "growth sales two years before recall") col(1)) name(grafico1, replace) 


twoway (kdensity log_lead_tot_sales if recalled_class_two ==1, lcolor(red) lpattern(solid)) (kdensity log_sales if recalled_class_two ==1,lcolor(blue) lwidth(medthin) lpattern(dash)) (kdensity log_lead2_tot_sales if recalled_class_t ==1, lcolor(green) lwidth(medium) lpattern(longdash_shortdash)), title(Sales (logarithmic scale):) subtitle(density one and two years after the recall)  ytitle(Density) xtitle(Logarithm of total sales) legend(order(1 "sales one year after recall" 2 "sales current year" 3 "growth sales two years after recall") col(1)) name(grafico2, replace)
May I repeat the exercise also for the background?

Thank you in advance,

Federico