我想在我的Gnuplot图表中包含png - 文件boompje.png，我使用以下代码行：
plot 'boompje.png' binary filetype=png origin=(120,-10) dx=0.008 dy=0.008 with rgbimage
问题在于，在我执行此操作后，y=0 - 行的颜色会变为黑色（see result），尽管我已将其声明为dark-plume。这是我的Gnuplotscript：
set term pngcairo size 1080,720
set output 'schuine_worp.png'
set size ratio -1
set xrange[0:250]
set yrange[-10:100]
set xlabel 'x (m)'
set ylabel 'y (m)'
set title 'schuine worp'
unset key
plot 'boompje.png' binary filetype=png origin=(120,-10) dx=0.008 dy=0.008 with rgbimage,\
'schuine_worp.dat' u 4:5 w p pt 7 ps 0.8,\
0 linecolor 'dark-plume' with filledcurves x1
为了完整起见，文件schuine_worp.dat：
time x0 y0 x1 y1 energy error step size
1e-05 121.1 -6370000 0.000290000000009342 0.000409999508613916 0 1e-05
0.200010000000059 121.1 -6370000 5.80029367739884 8.00383607717226 0 1e-05
0.400010000000259 121.1 -6370000 11.6003044702085 15.6141542714974 0 1e-05
0.600009999999904 121.1 -6370000 17.400322020473 22.8313655217641 1.81604519864699e-16 1e-05
0.800009999998994 121.1 -6370000 23.200345970239 29.6554707187308 1.81604519864699e-16 1e-05
1.00000999999808 121.1 -6370000 29.0003759615572 36.0864707046356 0 1e-05
1.20000999999939 121.1 -6370000 34.8004116364803 42.1243662731976 0 1e-05
1.4000100000007 121.1 -6370000 40.6004526370649 47.7691581696169 0 1e-05
1.60001000000201 121.1 -6370000 46.400498605369 53.0208470905712 0 1e-05
1.80001000000332 121.1 -6370000 52.2005491834544 57.879433684223 0 1e-05
2.00001000000464 121.1 -6370000 58.0006040133843 62.3449185502169 0 1e-05
2.20001000000595 121.1 -6370000 63.8006627372232 66.4173022396778 0 1e-05
2.40001000000726 121.1 -6370000 69.6007249970406 70.0965852552175 0 1e-05
2.60001000000857 121.1 -6370000 75.4007904349027 73.3827680509233 0 1e-05
2.80001000000988 121.1 -6370000 81.2008586928824 76.2758510323731 1.81604519864699e-16 1e-05
3.00001000001119 121.1 -6370000 87.0009294130507 78.7758345566268 0 1e-05
3.2000100000125 121.1 -6370000 92.8010022374819 80.8827189322266 1.81604519864699e-16 1e-05
3.40001000001381 121.1 -6370000 98.6010768082489 82.5965044192003 0 1e-05
3.60001000001512 121.1 -6370000 104.401152767427 83.91719122906 0 1e-05
3.80001000001643 121.1 -6370000 110.201229757093 84.8447795248006 0 1e-05
4.00001000001774 121.1 -6370000 116.001307419323 85.3792694209038 0 1e-05
4.20001000001017 121.1 -6370000 121.80138539619 85.5206609833359 0 1e-05
4.40001000000259 121.1 -6370000 127.60146332978 85.2689542295455 0 1e-05
4.60000999999502 121.1 -6370000 133.401540862163 84.6241491284684 0 1e-05
4.80000999998745 121.1 -6370000 139.201617635417 83.5862456005241 0 1e-05
5.00000999997988 121.1 -6370000 145.001693291617 82.1552435176159 0 1e-05
5.20000999997231 121.1 -6370000 150.801767472841 80.3311427031338 0 1e-05
5.40000999996474 121.1 -6370000 156.601839821162 78.113942931951 0 1e-05
5.60000999995716 121.1 -6370000 162.401909978656 75.5036439304269 0 1e-05
5.80000999994959 121.1 -6370000 168.201977587395 72.5002453764 0 1e-05
6.00000999994202 121.1 -6370000 174.00204228945 69.1037468991974 0 1e-05
6.20000999993445 121.1 -6370000 179.802103726892 65.3141480796298 0 1e-05
6.40000999992688 121.1 -6370000 185.60216154179 61.1314484499869 0 1e-05
6.60000999991931 121.1 -6370000 191.402215376209 56.5556474940451 0 1e-05
6.80000999991173 121.1 -6370000 197.202264872216 51.5867446470647 0 1e-05
7.00000999990416 121.1 -6370000 203.002309671869 46.2247392957841 0 1e-05
7.20000999989659 121.1 -6370000 208.802349417236 40.4696307784281 0 1e-05
7.40000999988902 121.1 -6370000 214.602383750372 34.3214183846989 1.81604519864699e-16 1e-05
7.60000999988145 121.1 -6370000 220.402412313331 27.780101355783 0 1e-05
7.80000999987388 121.1 -6370000 226.202434748166 20.8456788843452 0 1e-05
8.00000999986631 121.1 -6370000 232.002450696924 13.518150114531 0 1e-05
8.20000999985873 121.1 -6370000 237.802459801655 5.79751414196492 0 1e-05
8.40000999985116 121.1 -6370000 243.602461704401 -2.31622998624952 0 1e-05
8.60000999984359 121.1 -6370000 249.402456047201 -10.8230832715312 0 1e-05
8.80000999983602 121.1 -6370000 255.20244247209 -19.7230467638209 0 1e-05
9.00000999982845 121.1 -6370000 261.0024206211 -29.0161215615829 0 1e-05
9.20000999982088 121.1 -6370000 266.802390136256 -38.7023088118069 0 1e-05
9.4000099998133 121.1 -6370000 272.602350659585 -48.7816097100059 0 1e-05
9.60000999980573 121.1 -6370000 278.402301833104 -59.2540255002175 0 1e-05
9.80000999979816 121.1 -6370000 284.202243298828 -70.1195574750095 1.81604519864699e-16 1e-05
10.0000099997906 121.1 -6370000 290.002174698766 -81.3782069754736 1.81604519864699e-16 1e-05