Sampling black bar at x=360..400, y=500..560:
(360,500):166,127,60 (365,500):158,119,52 (370,500):152,112,50 (375,500):143,103,41 (380,500):140,100,38 (385,500):130,95,31 (390,500):126,87,28 (395,500):48,27,0 (400,500):25,18,8 
(360,510):178,140,69 (365,510):174,136,65 (370,510):167,128,61 (375,510):160,121,54 (380,510):156,117,50 (385,510):144,109,41 (390,510):134,96,33 (395,510):55,34,3 (400,510):25,18,8 
(360,520):194,157,86 (365,520):186,149,78 (370,520):181,142,73 (375,520):179,140,71 (380,520):170,131,62 (385,520):158,121,53 (390,520):148,109,42 (395,520):52,32,0 (400,520):22,18,7 
(360,530):196,162,91 (365,530):200,166,95 (370,530):199,165,94 (375,530):193,159,88 (380,530):186,149,79 (385,530):175,138,68 (390,530):167,127,58 (395,530):47,28,0 (400,530):23,16,8 
(360,540):216,182,111 (365,540):215,181,110 (370,540):205,171,100 (375,540):203,169,98 (380,540):200,163,93 (385,540):202,165,95 (390,540):188,148,79 (395,540):49,30,0 (400,540):25,18,10 
(360,550):226,192,121 (365,550):220,186,115 (370,550):224,190,119 (375,550):222,188,117 (380,550):223,189,118 (385,550):209,176,105 (390,550):195,158,87 (395,550):52,36,0 (400,550):26,22,13